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In this study, we intended to investigate the responses of rhizospheric bacterial communities of Populus cathayana to excess Zn under different planting patterns. The results suggested that intersexual and intrasexual interactions strongly affect plant growth and Zn extraction in both sexes, as well as rhizosphere-associated bacterial community structures. Females had a higher capacity of Zn accumulation and translocation than males under all planting patterns. Males had lower Zn accumulation and translocation under intersexual than under intrasexual interaction; the contrary was true for females. Females harbored abundant Streptomyces and Nocardioides in their rhizosphere, similarly to males under intersexual interaction, but differed from single-sex males under excess Zn. Conversely, intersexual interaction increased the abundance of key taxa Actinomycetales and Betaproteobacteria in both sexes exposed to excess Zn. Males improved the female rhizospheric microenvironment by increasing the abundance of some key tolerance taxa of Chloroflexi, Proteobacteria and Actinobacteria in both sexes under excess Zn in intersexual interaction. These results indicated that the sex of neighboring plants affected sexual differences in the choice of specific bacterial colonizations for phytoextraction and tolerance to Zn-contaminated soils, which might regulate the spatial segregation and phytoremediation potential of P. cathayana females and males under heavy metal contaminated soils.
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Intra- and intersexual interactions shape microbial community dynamics in the rhizosphere of Populus cathayana females and males exposed to excess Zn.
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Journal of hazardous materials
|
chemistry
| 1,530 | 13 |
Herein, a novel "waste reclamation for soil remediation" strategy has been developed for both alkaline waste red mud (RM) recycling and heavy metal (HM) polluted soil remediation. Through a direct one-pot hydrothermal reaction process, the Al, Si, alkali, and Fe 2 O 3 components in waste RM have been transferred into ferric oxide decorated ANA-type zeolite (Fe 2 O 3 -ANA). As tested by the HMs polluted soil remediation and oilseed rape planting experiment, when 25 g/kg Fe 2 O 3 -ANA is added into the Pb 2+ , Cu 2+ , Cr 3+ and anionic AsO 2 - polluted soil (HM concentration: 100-200 mg/kg), it can effectively suppress the HMs mobility in soil and reduce the bio-accumulation concentrations of HMs in the harvested oilseed rape (reduce ratio: 37.9-69.5%). The detailed mechanism study using energy dispersive X-ray energy spectroscopy, in-depth X-ray photoelectron spectroscopy and density function theory calculation concludes that the Cu 2+ , Pb 2+ and Cr 3+ in soil have been adsorbed and trapped in the framework structure of ANA in Fe 2 O 3 -ANA mainly via the cation exchange process. While the anionic AsO 2 - species are mainly caught by the Fe 2 O 3 component in Fe 2 O 3 -ANA via surface adsorption. Overall, this work firstly transforms waste RM into Fe 2 O 3 -ANA for soil remediation, which is valuable to waste resource recycling and environmental conservation.
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Transferring waste red mud into ferric oxide decorated ANA-type zeolite for multiple heavy metals polluted soil remediation.
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Journal of hazardous materials
|
chemistry
| 1,530 | 13 |
Perfluorooctanoic acid (PFOA), as a typical emerging organic pollutant, can interact with serum albumin. However, it remains to characterize the binding of PFOA with serum albumin and to address the role of this interaction in related toxic effects. We aimed to characterize the interaction between PFOA and albumin for understanding the effects of this interaction on the uptake, distribution, and toxicity of PFOA in human cells. The results showed that viable cell count was significantly enhanced by addition of fetabl bovine serum (FBS) into cell culture medium with 300 μM PFOA treatment. PFOA mainly existed as complexed with FBS, at FBS concentration > 10%, which substantially reduced the absorption efficiency of all cell lines to PFOA. The majority of PFOA was accumulated in the cytosolic fraction, followed by nuclei, and mitochondria. Conclusively, our study suggests that the complexation of organic contaminants with proteins might mitigate their toxicity by reducing cellular uptake.
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Fetal bovine serum attenuating perfluorooctanoic acid-inducing toxicity to multiple human cell lines via albumin binding.
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Journal of hazardous materials
|
chemistry
| 1,530 | 13 |
Alumina nanoparticles (AlNPs) exposure causes hippocampal-dependent cognitive dysfunction. However, whether chronic stress exacerbates AlNPs-induced hippocampal lesion and its mechanism remains unclear. This study was aimed to investigate the combined effects and mechanisms of AlNPs and chronic stress on the hippocampal lesion. The behavioral tests demonstrated that combined exposure to AlNPs and chronic restraint stress (CRS) worsened both cognition and depression-like behavior than exposed to AlNPs and CRS alone. Microstructural and ultrastructural observations showed that combined exposure to AlNPs and CRS exacerbated hippocampal damage. Both AlNPs and CRS induced hippocampal neuronal ferroptosis, presenting as iron and glutamate metabolism disorder, GPX4 fluorescence of neurons decrease, LPO and ROS levels increase, and FJB-positive neurons increase. Meanwhile, combined exposure to AlNPs and CRS exacerbated hippocampal neuronal ferroptosis. Mechanism investigation revealed that combined exposure to AlNPs and CRS activated IFN-γ/ASK1/JNK signaling pathway. Furthermore, IFN-γ neutralizing antibody R4-6A2 effectively inhibited the activation of IFN-γ/ASK1/JNK signaling pathway, alleviated hippocampal neuronal ferroptosis and improved cognition ability. ASK1 inhibitor GS-4997 also improved hippocampal neuronal ferroptosis and cognitive dysfunction by inhibiting ASK1/JNK signaling pathway. Together, these results demonstrate that combined exposure to AlNPs and CRS exacerbates hippocampal neuronal ferroptosis via activating IFN-γ/ASK1/JNK signaling pathway.
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Combined exposure of alumina nanoparticles and chronic stress exacerbates hippocampal neuronal ferroptosis via activating IFN-γ/ASK1/JNK signaling pathway in rats.
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Journal of hazardous materials
|
chemistry
| 1,530 | 13 |
The fate and transport of semi-volatile organic compounds (SVOCs) in residential environments is significantly influenced by emission and sorption processes, which can be characterized by three key parameters: the gas-phase SVOC concentration adjacent to the material surface (y 0 ); the diffusion coefficient (D m ); and the partition coefficient (K). Accurate determination of these three key parameters is critical for investigating SVOC mass transfer principles, and for assessing human health risks. Based on the mass transfer process of phthalates in a ventilated chamber, a novel method is developed to simultaneously measure D m and K (key sorption parameters) in sink materials. The D m and K of four target phthalates in a common T-shirt (sink material) are determined, and compared with those reported in literature. Results demonstrate that the measured parameters are in good agreement with those previously reported (relative deviation < 20 %), validating the effectiveness of proposed method. In addition, this method can be applied to determine y 0, a key parameter from source materials. Results indicate that y 0 determined with this method is consistent with that measured by literature method. Finally, dermal exposure analysis is performed, showing that dermal uptake of target phthalates is greatly affected by clothes.
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Characterization of phthalates in sink and source materials: Measurement methods and the impact on exposure assessment.
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Journal of hazardous materials
|
chemistry
| 1,530 | 13 |
Realgar is a traditional Chinese medicine containing arsenic and has neurotoxicity. This study used realgar exposure mice model, neurobehavioral tests, analytical chemistry, molecular biology and nontargeted lipidomics to explore the mechanism of realgar damages the nervous system. The arsenic contained in realgar passed through the BBB and accumulated in the brain. Neurons, synapses and myelin showed abnormal changes in the cerebral cortex. The number of autophagosomes were incresed as well as levels of MDA, Lp-PLA2, and cPLA2 but the CAT level was significant reduced. Finally, the cognition and memory of mice were decreased. Nontargeted lipidomics detected 34 lipid subclasses including 1603 lipid molecules. The levels of the LPC and LPE were significantly increased. Under the condition of variable importance for the projection (VIP)>1 and P < 0.05, only 28 lipid molecules satisfied the criteria. The lipid molecular markers SM (d36:2), PE (18:2/22:6) and PE (36:3) which were filtered by receiver operating characteristic (ROC) curve (AUC>0.8 or AUC<0.2) were used to identify the neurotoxicity induced by realgar. Therefore, realgar induces neurotoxicity through exacerbating oxidative damage and lipid dysfunction. Providing research basis for the clinical diagnosis and treatment of realgar-induced neurotoxicity.
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Identification of neurotoxicity markers induced by realgar exposure in the mouse cerebral cortex using lipidomics.
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Journal of hazardous materials
|
chemistry
| 1,530 | 13 |
Uptake of hazardous metal(loid)s adversely affects plants and imposes a threat to the entire food chain. Here, the role of aquaporins (AQPs) providing tolerance against hazardous metal(loid)s in plants is discussed to provide a perspective on the present understanding, knowledge gaps, and opportunities. Plants adopt complex molecular and physiological mechanisms for better tolerance, adaptability, and survival under metal(loid)s stress. Water conservation in plants is one such primary strategies regulated by AQPs, a family of channel-forming proteins facilitating the transport of water and many other solutes. The strategy is more evident with reports suggesting differential expression of AQPs adopted by plants to cope with the heavy metal stress. In this regard, numerous studies showing enhanced tolerance against hazardous elements in plants due to AQPs activity are discussed. Consequently, present understanding of various aspects of AQPs, such as tertiary-structure, transport activity, solute-specificity, differential expression, gating mechanism, and subcellular localization, are reviewed. Similarly, various tools and techniques are discussed in detail aiming at efficient utilization of resources and knowledge to combat metal(loid)s stress. The scope of AQP transgenesis focusing on heavy metal stresses is also highlighted. The information provided here will be helpful to design efficient strategies for the development of metal(loid)s stress-tolerant crops.
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Targeting aquaporins to alleviate hazardous metal(loid)s imposed stress in plants.
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Journal of hazardous materials
|
chemistry
| 1,530 | 13 |
Layered double hydroxides (LDHs) are very promising adsorbents for the removal of anionic pollutants from water. However, the low adsorption efficiency and recycling difficulty of conventional LDH powders are obstacles to practical applications. Herein, a novel Zn/Fe-LDH composite sponge was successfully fabricated using a simple in-situ hydrothermal method. Characterization studies revealed that the composite sponge contained flower-like Zn/Fe LDH microspheres uniformly dispersed throughout a poly vinyl alcohol (PVA) sponge matrix. The specific surface area of the Zn/Fe-LDH composite sponge was 42.5 m 2 g -1 , approximately 5 times higher than the pristine PVA sponge (8.9 m 2 g -1 ). Adsorption experiments revealed that Zn/Fe-LDH composite sponge exhibited a much higher adsorption ability for As(V) anions and methyl orange (MO) compared with a Zn/Fe-LDH powder or the pristine PVA sponge. The maximum adsorption capacity for As(V) was found to be 85.7 mg g -1 . Furthermore, the Zn/Fe-LDH composite sponge showed high thermal stability, good mechanical stability and easy recoverability, thereby allowing reuse. Results guide the development of improved, low cost water treatment materials.
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Recyclable polyvinyl alcohol sponge containing flower-like layered double hydroxide microspheres for efficient removal of As(V) anions and anionic dyes from water.
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Journal of hazardous materials
|
chemistry
| 1,530 | 13 |
Here we report that nanoclay-polyphenol-polymer hybrid sensing channels can greatly enhance the sensitivity for hazardous reactive oxygen species (ROS) in organic field-effect transistor (OFET) sensors. The hybrid layers were prepared by introducing nanoclay into the binary mixtures of poly(3-hexylthiophene) (P3HT) and rutin (a polyphenol) at various weight ratios. The presence of nanoclay improved the P3HT crystallinity in the hybrid films, which contributed to the increased drain current and well-maintained hole mobility even at the reduced amount of charge-transporting P3HT part. At the best composition (P3HT:rutin:nanocaly = 10:1:2 by weight), the OFETs with the hybrid layers were able to sense even 1 nM superoxide (a ROS) and exhibited pronouncedly enhanced sensitivity compared to those without nanoclay. The morphology investigation disclosed that rutin-nanoclay complexes formed in the hybrid films might be responsible for the enhanced sensitivity, because they let more rutin molecules protrude on the surface of channel layers for reactions with superoxide.
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Enhanced superoxide sensitivity in organic field-effect transistor sensors by introducing nanoclay-polyphenol-polymer hybrid sensing channels.
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Journal of hazardous materials
|
chemistry
| 1,530 | 13 |
Hydrodynamic cavitation is an effective advanced oxidation process. But sometimes it cannot obtain satisfactory treatment efficiency by using hydrodynamic cavitation individually, so it is necessary to introduce intensive methods. Based on double-cavitating-jets impingement, this paper presents a novel device that has advantages of strong heat and mass transfer and efficient chemical reactions. Based on the device, a series of experimental investigations on degradation of a basic dye, i.e. Rhodamine B were carried out. Significant Rhodamine B removal from aqueous solution was observed during 2h treatment and the degradation reaction conformed to pseudo-first-order kinetics. The synergetic effects between double-cavitating-jets impingement and Fenton chemistry on simultaneous degradation of Rhodamine B were confirmed. Both single-variable experiments and orthogonal experiments were carried out to study the effects of initial hydrogen peroxide, ferrous sulfate and Rhodamine B concentrations and the optimum conditions were found out. Effects of jet inlet pressure in the range of 6-12MPa and solution pH value in the range of 2-8 were also investigated. The cavitation yield was evaluated to assess the energy efficiency. The present treatment scheme showed advantages in terms of reducing the demand of hydrogen peroxide concentration and enhancing the treatment efficiency in large scale operation.
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A novel device for hazardous substances degradation based on double-cavitating-jets impingement: Parameters optimization and efficiency assessment.
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Journal of hazardous materials
|
chemistry
| 1,530 | 13 |
Due to the huge threat of formaldehyde (FA) on human beings, the development of chemical sensors for swift detection of FA in solutions and gas phase is highly anticipated. In this paper, a versatile logic detector and a portable fluorescent film based on small-scaled Eu-based MOF were applied successfully to detect FA in solutions and gas phase, respectively. For FA in aqueous solution, the design of logic detector will efficiently identify FA in different concentration ranges: when the FA concentration are 0-500 ppb, 500-1000 ppb and >1000 ppb, the output signals of logic detector are the concentration level of FA ("L", "H" and "VH"), and accompanied by red, purple and blue signal lamps to remind, respectively. For FA in the air, the color of rigid film sensor will gradually change from red to blue with the increase of FA under UV lamp, and the detection limit of gaseous FA is 11.8 ppb. Through the preparation of logic devices and fluorescent films, Eu-based MOF realized swift detection of FA in solutions and gas phase, which will be very helpful to improve the human response level to FA from different emission sources.
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A versatile logic detector and fluorescent film based on Eu-based MOF for swift detection of formaldehyde in solutions and gas phase.
|
Journal of hazardous materials
|
chemistry
| 1,530 | 13 |
Carcinogenic GenX chemicals, heptafluoropropylene-oxide-dimer-acid (HFPO-DA), have been recently detected in surface, ground and recycled water sources worldwide. However, GenX removals under the influence of variable characteristics of the organic and inorganic compounds present in the natural water sources, have often been overlooked in scientific literature. This is critically important given that the ionic composition and characteristics of organic matter in natural waters are spatially and seasonally variable. A strongly basic anion exchange (IX) resin was used to remove GenX and two other perfluorinated ether acids (PFEAS) from natural surface and recycled water sources. Factors influencing the uptake behavior included the PFEAS concentrations, resin dosage, and background anion characteristics. The equivalent background compound was employed to evaluate the competitive uptake between natural organic matter (NOM), inorganic ions and PFEAS in natural water matrices. Experimental data were compared with different mathematical and physical models and it was depicted that approximately 4-6% of the initial NOM competed with PFEAS for active exchange sites. Further, IX was able to achieve complete PFEAS removal (C final <10 ng/L) with simultaneous removal of>60% NOM and >80% inorganic ions. Results of this study indicate that IX exhibits great potential for PFEAS removal from natural drinking water sources.
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Efficient removal of GenX (HFPO-DA) and other perfluorinated ether acids from drinking and recycled waters using anion exchange resins.
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Journal of hazardous materials
|
chemistry
| 1,530 | 13 |
Uranium minerals are commonly found in soils and sediment across the United States at an average concentration of 2-4 mg/kg. Uranium occurs in the environment primarily in two forms, the oxidized, mostly soluble uranium(VI) form, or the reduced, sparingly soluble reduced uranium(IV) form. Here we describe subsurface geochemical conditions that result in low uranium concentrations in an alluvial aquifer with naturally occurring uranium in soils and sediments in the presence of complexing ligands under oxidizing conditions. Groundwater was saturated with respect to calcite and contained calcium (78-90 mg/L) with elevated levels of carbonate alkalinity (291-416 mg/L as HCO 3 - ). X-ray adsorption near edge structure (XANES) spectroscopy identified that sediment-associated uranium was oxidized as a uranium(VI) form (85%). Calcite was the predominant mineral by mass in the ultrafine fraction in uranium-bearing sediments (>16 mg/kg). Groundwater geochemical modeling indicated calcite and/or a calcium-uranyl-carbonate mineral such as liebigite in equilibrium with groundwater. The δ 13 C (0.57‰ ± 0.15‰) was indicative of abiotic carbonate deposition. Thus, solid-phase uranium(VI) associated with carbonate is likely maintaining uranium(VI) groundwater levels below the maximum contaminant level (MCL; 30 µg/L), presenting a deposition mechanism for uranium attenuation rather than solely a means of mobilization.
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Uranium(VI) attenuation in a carbonate-bearing oxic alluvial aquifer.
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Journal of hazardous materials
|
chemistry
| 1,530 | 13 |
Lead (Pb) is a common pollutant in many environments, including in the soil, water, and/or air. Typha orientalis Presl, a large emergent aquatic plant, has been reported to function as a Pb-tolerant and Pb-accumulating plant; however, very little molecular information regarding the tolerance of T. orientalis towards Pb is known. In this study, Pb accumulation and key factors involved in the Pb stress response at different Pb concentrations were investigated. Pb was primarily accumulated in the roots and was mainly located in the cell wall and membrane systems. Differentially expressed genes (DEGs) were identified in T. orientalis roots after Pb exposure via RNA-seq analyses. In the 0.10 mM and 0.25 mM Pb 2+ -treated groups, a total of 3275 DEGs were detected relative to the control. Many of these genes were associated with oxidation-reduction processes, metal transport, protein kinase/phosphorylation, and DNA binding transcription factors, which were shown to be Pb-responsive DEGs. Mapping Kyoto Encyclopedia of Genes and Genomes (KEGG) database, "phenylpropanoid biosynthesis" was analyzed as the major pathway of the important modules of overlapping DEGs of 0.10 mM and 0.25 mM Pb 2+ treatments. Furthermore, a lead response gene named ToLR1 with unknown function was of particular interest. The full-length of ToLR1 sequence was cloned using rapid amplification of cDNA ends (RACE) and overexpressed in Arabidopsis thaliana, which resulted in enhanced resistance to Pb stress. This is the first report providing genomic information detailing Pb responsive genes in T. orientalis. Moreover, this study provides novel insights into the molecular mechanisms underlying the response of T. orientalis and other accumulators towards Pb stress. The key genes identified in this study may serve as potential targets for genetic engineering targeting phytoremediation.
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Transcriptome -wide modulation combined with morpho-physiological analyses of Typha orientalis roots in response to lead challenge.
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Journal of hazardous materials
|
chemistry
| 1,530 | 13 |
New thin BiVO 4 film using facile water‒based electrophoretic deposition process was synthesized on the webbed stainless steel surface. This work can be considered as a green method owing to use of safe, non-flammable, and cheap media of water as solvent of electrophoretic deposition. Structural and morphological properties of the resultant film were studied by X-ray diffraction (XRD), Raman spectroscopy, Scanning Electron Microscopy (SEM), Elemental and Mapping analyses (EDS), Optical Microscopy, Atomic Force Microscopy (AFM), and X-ray Photoelectron Spectroscopy (XPS) analysis. The moderate diameter size of nanorods of the deposited BiVO 4 was measured in the range of 100 to 150 nm. The prepared three layered thin film was shown permanent photocatalytic degradation rate of Amoxicillin pharmaceutical pollution as high as 97.45 % after 90 min. It can be suggested that BiVO 4 nanorods have the high ability of hole-electron separation and electron transferring through the alternative routes. Indeed, the prepared thin films of BiVO4 having nanoroad morphology possess great potential for light harvesting. Moreover, webbed stainless steel with electron acceptor character leads to severe separation of photogenerated hole‒electron. The mechanistic study of the scavenging reaction introduced the hydroxyl radicals as the main specie in the photocatalytic process. It is interesting that obtained results of photocatalytic process of this BVO film within different pollutants (dyes, phenol, and drugs) demonstrated the high efficiency and mineralization rate.
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New water based EPD thin BiVO4 film: Effective photocatalytic degradation of Amoxicillin antibiotic.
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Journal of hazardous materials
|
chemistry
| 1,530 | 13 |
How to efficiently treat radioactive uranium-containing nuclear wastewater is one of the significant challenges to ensure the safety of nuclear technology and to avoid environmental pollution. Here we firstly prepare the metal-free 2D/2D C 3 N 5 /GO nanosheets, and customize a type-II heterojunction based on the band bending theory to achieve enhanced uranium extraction capacity via synergistic adsorption photoreduction engineering. The structure of C 3 N 5 is explained by electron energy loss spectroscopy and synchrotron-based near-edge X-ray absorption fine structure. And C 3 N 5 with larger π-conjugated structure expands the light response range to 747 nm, which is about 1.67 times that of C 3 N 4 . Further, we also use density functional theory to prove the existence of alternating energy levels so that photogenerated electrons could be continuously injected into the surface of GO to ensure the effective separation of electron-hole pairs and increase the material activity. The results show that the removal ratio of uranium by 2D/2D C 3 N 5 /GO heterojunction is achieved as high as 96.1% even at a low uranium concentration of 10 ppm, and reached 93.4% after exposure to gamma-ray. This work will lay a foundation for customizing the energy band structure of nonmetal-based 2D/2D nanohybrids and enriching uranium-containing wastewater through adsorption photoreduction engineering in the future.
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Metal-free 2D/2D C3N5/GO nanosheets with customized energy-level structure for radioactive nuclear wastewater treatment.
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Journal of hazardous materials
|
chemistry
| 1,530 | 13 |
Many studies have proved the impacts of nanoplastic pollution in freshwaters on aquatic organisms and ecosystems. To explore toxic mechanisms of nanoplastics on stream functioning, we conducted a microcosm experiment to investigate the effects of polystyrene nanoparticles (PS NPs, 1-100 μg L -1 ) on the process of leaf litter decomposition mediated by the microbial community. The chronic exposure to PS NPs at 1 and 100 μg L -1 caused significant decreases in leaf litter decomposition and nutrient (carbon and nitrogen) releases. During the ecological process, some extracellular enzymes (i.e., β-glucosidase, glycine-aminopeptidase, and phenol oxidase) rather than fungal biomass were suppressed. Besides, decreases in the relative abundance of Anguillospora and Setophaeosphaeria weakened their functions in leaf litter decomposition. Thus, the microcosm experiment showed that PS NPs inhibited stream leaf decomposition by modulating the microbial metabolic activity and fungal community structure. Overall, the results of this study provide evidence for the consequences of nanoplastic pollution on freshwater microbial community and stream ecosystem functioning, which is conducive to evaluate the potential risks of nanoplastics in aquatic environments.
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Nanoplastic pollution inhibits stream leaf decomposition through modulating microbial metabolic activity and fungal community structure.
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Journal of hazardous materials
|
chemistry
| 1,530 | 13 |
Small-arm shooting ranges often receive a significant input of lead (Pb), copper (Cu) and antimony (Sb) from ammunition. The goal of the present study was to investigate the mobility, distribution and speciation of Pb and Sb pollution under field conditions in both untreated and sorbent-amended shooting range soil. Elevated Sb (19-349μgL(-1)) and Pb (7-1495μgPbL(-1)) concentrations in the porewater of untreated soil over the four-year test period indicated a long-term Sb and Pb source to the adjacent environment in the absence of remedial measures. Mixing ferric oxyhydroxide powder (CFH-12) (2%) together with limestone (1%) into the soil resulted in an average decrease of Sb and Pb porewater concentrations of 66% and 97%, respectively. A similar reduction was achieved by adding 2% zerovalent iron (Fe°) to the soil. The remediation effect was stable over the four-year experimental period indicating no remobilization. Water- and 1M NH4NO3-extractable levels of Sb and Pb in field soil samples indicated significant immobilization by both treatments (89-90% for Sb and 89-99% for Pb). Results from sequential extraction analysis indicate fixation of Sb and Pb in less accessible fractions like amorphous iron oxides or even more crystalline and residual mineral phases, respectively. This work shows that amendment with Fe-based sorbents can be an effective method to reduce the mobility of metals both in cationic and anionic form in polluted shooting range soil.
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Antimony (Sb) and lead (Pb) in contaminated shooting range soils: Sb and Pb mobility and immobilization by iron based sorbents, a field study.
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Journal of hazardous materials
|
chemistry
| 1,530 | 13 |
Soybean cyst nematode (SCN, Heterodera glycines ) has become the major yield-limiting biological factor in soybean production. Common bean is also a good host of SCN, and its production is challenged by this emerging pest in many regions such as the upper Midwest USA. The use of host genetic resistance has been the most effective and environmentally friendly method to manage SCN. The objectives of this study were to evaluate the SCN resistance in the USDA common bean core collection and conduct a genome-wide association study (GWAS) of single nucleotide polymorphism (SNP) markers with SCN resistance. A total of 315 accessions of the USDA common bean core collection were evaluated for resistance to SCN HG Type 0 (race 6). The common bean core set was genotyped with the BARCBean6K_3 Infinium BeadChips, consisting of 4,654 SNPs. Results showed that 15 accessions were resistant to SCN with a Female Index (FI) at 4.8 to 9.4, and 62 accessions were moderately resistant (10 < FI < 30) to HG Type 0. The association study showed that 11 SNP markers, located on chromosomes Pv04, 07, 09, and 11, were strongly associated with resistance to HG Type 0. GWAS was also conducted for resistance to HG Type 2.5.7 and HG Type 1.2.3.5.6.7 based on the public dataset ( N = 276), consisting of a diverse set of common bean accessions genotyped with the BARCBean6K_3 chip. Six SNPs associated with HG Type 2.5.7 resistance on Pv 01, 02, 03, and 07, and 12 SNPs with HG Type 1.2.3.5.6.7 resistance on Pv 01, 03, 06, 07, 09, 10, and 11 were detected. The accuracy of genomic prediction (GP) was 0.36 to 0.49 for resistance to the three SCN HG types, indicating that genomic selection (GS) of SCN resistance is feasible. This study provides basic information for developing SCN-resistant common bean cultivars, using the USDA core germ plasm accessions. The SNP markers can be used in molecular breeding in common beans through marker-assisted selection (MAS) and GS.
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Genome-Wide Association Study and Genomic Prediction for Soybean Cyst Nematode Resistance in USDA Common Bean (Phaseolus vulgaris) Core Collection.
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Frontiers in plant science
|
plant
| 1,000 | 57 |
Studies of the anther transcriptome on non-model plants without a known genome are surprisingly scarce. RNA-Seq and digital gene expression (DGE) profiling provides a comprehensive approach to identify candidate genes contributing to developmental processes in non-model species. Here we built a transcriptome library of developing anthers of Hamelia patens and analyzed DGE profiles from each stage to identify genes that regulate tapetum and pollen development. In total 7,720 putative differentially expressed genes across four anther stages were identified. The number of putative stage-specific genes was: 776 at microspore mother cell stage, 807 at tetrad stage, 322 at uninucleate microspore stage, and the highest number (1,864) at bicellular pollen stage. GO enrichment analysis revealed 243 differentially expressed and 108 stage-specific genes that are potentially related to tapetum development, sporopollenin synthesis, and pollen wall. The number of expressed genes, their function and expression profiles were all significantly correlated with anther developmental processes. Overall comparisons of anther and pollen transcriptomes with those of rice and Arabidopsis together with the expression profiles of homologs of known anther-expressed genes, revealed conserved patterns and also divergence. The divergence may reflect taxon-specific differences in gene expression, the use RNA-seq as a more sensitive methodology, variation in tissue composition and sampling strategies. Given the lack of genomic sequence, this study succeeded in assigning putative identity to a significant proportion of anther-expressed genes and genes relevant to tapetum and pollen development in H. patens. The anther transcriptome revealed a molecular distinction between developmental stages, serving as a resource to unravel the functions of genes involved in anther development in H. patens and informing the analysis of other members of the Rubiaceae.
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Transcriptome Analysis of Hamelia patens (Rubiaceae) Anthers Reveals Candidate Genes for Tapetum and Pollen Wall Development.
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Frontiers in plant science
|
plant
| 1,000 | 57 |
WRINKLED1 (WRI1), a member of the APETALA2 (AP2) class of transcription factors regulates fatty acid biosynthesis and triacylglycerol (TAG) accumulation in plants. Among the four known Arabidopsis WRI1 paralogs, only WRI2 was unable to complement and restore fatty acid content in wri1-1 mutant seeds. Avocado ( Persea americana ) mesocarp, which accumulates 60-70% dry weight oil content, showed high expression levels for orthologs of WRI2 , along with WRI1 and WRI3 , during fruit development. While the role of WRI1 as a master regulator of oil biosynthesis is well-established, the function of WRI1 paralogs is poorly understood. Comprehensive and comparative in silico analyses of WRI1 paralogs from avocado (a basal angiosperm) with higher angiosperms Arabidopsis (dicot), maize (monocot) revealed distinct features. Predictive structural analyses of the WRI orthologs from these three species revealed the presence of AP2 domains and other highly conserved features, such as intrinsically disordered regions associated with predicted PEST motifs and phosphorylation sites. Additionally, avocado WRI proteins also contained distinct features that were absent in the nonfunctional Arabidopsis ortholog At WRI2. Through transient expression assays, we demonstrated that both avocado WRI1 and WRI2 are functional and drive TAG accumulation in Nicotiana benthamiana leaves. We predict that the unique features and activities of ancestral PaWRI2 were likely lost in orthologous genes such as AtWRI2 during evolution and speciation, leading to at least partial loss of function in some higher eudicots. This study provides us with new targets to enhance oil biosynthesis in plants.
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Functional and Predictive Structural Characterization of WRINKLED2, A Unique Oil Biosynthesis Regulator in Avocado.
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Frontiers in plant science
|
plant
| 1,000 | 57 |
Autophagy is an intracellular trafficking and degradation system for recycling of damaged organelles, mis-folded proteins and cytoplasmic constituents. Autophagy can be divided into non-selective autophagy and selective autophagy according to the cargo specification. Key to the process is the timely formation of the autophagosome, a double-membrane structure which is responsible for the delivery of damaged organelles and proteins to lysosomes or vacuoles for their turnover. Autophagosomes are formed by the closure of cup-shaped phagophore which depends on the proper communication with membrane contributors. The endoplasmic reticulum (ER) is a major membrane source for autophagosome biogenesis whereby the ER connects with phagophore through membrane contact sites (MCSs). MCSs are closely apposed domains between organelle membranes where lipids and signals are exchanged. Lipid transfer proteins (LTPs) are a large family of proteins including Oxysterol-binding protein related proteins (ORP) which can be found at MCSs and mediate lipid transfer in mammals and yeast. In addition, interaction between autophagosomes and other organelles can also be detected in selective autophagy for selection and degradation of various damaged organelles. Selective autophagy is mediated by the binding of a receptor or an adaptor between a cargo and an autophagosome. Here we summarize what we know about the MCS between autophagosomes and other organelles in eukaryotes. We then discuss progress in our understanding about ORPs at MCSs in plants and the underlying mechanisms of selective autophagy in plants with a focus on receptors/adaptors that are involved in the interaction of the autophagosome with other cytoplasmic constituents, including the Neighbor of BRCA1 gene 1 (NBR1), ATG8-interacting protein 1 (ATI1), Regulatory Particle Non-ATPase 10 (RPN10), and Dominant Suppressor of KAR2 (DSK2).
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Membrane Contact Sites and Organelles Interaction in Plant Autophagy.
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Frontiers in plant science
|
plant
| 1,000 | 57 |
Plant proteases are key regulators of plant cell processes such as seed development, immune responses, senescence and programmed cell death (PCD). Apoplastic papain-like cysteine proteases (PL) are hubs in plant-microbe interactions and play an important role during abiotic stresses. The apoplast is a crucial interface for the interaction between plant and microbes. So far, apoplastic maize PL and their function have been mostly described for aerial parts. In this study, we focused on apoplastic PLCPs in the roots of maize plants. We have analyzed the phylogeny of maize PLCPs and investigated their protein abundance after salicylic acid (SA) treatment. Using activity-based protein profiling (ABPP) we have identified a novel root-specific PLCP belonging to the RD21-like subfamily, as well as three SA activated PLCPs. The root specific PLCP CP1C shares sequence and structural similarities to known CP1-like proteases. Biochemical analysis of recombinant CP1C revealed different substrate specificities and inhibitor affinities compared to the related proteases. This study characterized a root-specific PLCP and identifies differences between the SA-dependent activation of PLCPs in roots and leaves.
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Proteases Underground: Analysis of the Maize Root Apoplast Identifies Organ Specific Papain-Like Cysteine Protease Activity.
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Frontiers in plant science
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plant
| 1,000 | 57 |
The aim of this study was to explore the effects of different density treatments on potato spatial distribution and yield in spring and fall. Plant density influenced yield and composition, horizontal, and vertical distribution distances between potato tubers, and spatial distribution position of tuber weights. The results indicated that: (1) Spring potato yield had a convex quadratic curve relationship with density, and the highest value was observed at 15.75 × 10(4) tubers per hectare. However, the yield of fall potatoes showed a linear relationship with plant density, and the highest value was observed at 18 × 10(4) tubers per hectare; (2) Density had a greater influence on the tuber weight of spring potatoes and fruit number of single fall potatoes; (3) The number of potato tubers in the longitudinal concentration exhibited a negative linear relationship with density, whereas the average vertical distribution distance of tubers exhibited a positive incremental hyperbolic relationship. For spring and fall potato tubers, the maximum distances were 8.4152 and 6.3316 cm, and the minimum distances 8.7666 and 6.9366 cm, respectively; and (4) Based on the artificial neural network model of the spatial distribution of tuber weight, density mainly affected the number and spatial distribution of tubers over 80 g. Tubers over 80 g were mainly distributed longitudinally (6-10 cm) and transversely (12-20 cm) within the high density treatment, and the transverse distribution scope and number of tubers over 80 g were reduced significantly. Spring potato tubers over 80 g grown at the lowest density were mainly distributed between 12 and 20 cm, whereas those at the highest density were primarily distributed between 10 and 15 cm.
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Response of Potato Tuber Number and Spatial Distribution to Plant Density in Different Growing Seasons in Southwest China.
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Frontiers in plant science
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plant
| 1,000 | 57 |
Mechanisms underlying plant non-host resistance to Xanthomonas oryzae pv. oryzicola ( Xoc ), the pathogen causing rice leaf streak disease, are largely unknown. Cyclic nucleotide-gated ion channels (CNGCs) are calcium-permeable channels that are involved in various biological processes including plant resistance. In this study, functions of two tomato CNGC genes SlCNGC1 and SlCNGC14 in non-host resistance to Xoc were analyzed. Silencing of SlCNGC1 and SlCNGC14 in tomato significantly enhanced Xoc -induced hypersensitive response (HR) and non-host resistance, demonstrating that both SlCNGC1 and SlCNGC14 negatively regulate non-host resistance related HR and non-host resistance to Xoc in tomato. Silencing of SlCNGC1 and SlCNGC14 strikingly increased Xoc -induced callose deposition and strongly promoted both Xoc -induced and flg22-elicited H 2 O 2 , indicating that these two SlCNGCs repress callose deposition and ROS accumulation to attenuate non-host resistance and PAMP-triggered immunity (PTI). Importantly, silencing of SlCNGC1 and SlCNGC14 apparently compromised cytosolic Ca 2+ accumulation, implying that SlCNGC1 and SlCNGC14 function as Ca 2+ channels and negatively regulate non-host resistance and PTI-related responses through modulating cytosolic Ca 2+ accumulation. SlCNGC14 seemed to play a stronger regulatory role in the non-host resistance and PTI compared to SlCNGC1 . Our results reveal the contribution of CNGCs and probably also Ca 2+ signaling pathway to non-host resistance and PTI.
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SlCNGC1 and SlCNGC14 Suppress Xanthomonas oryzae pv. oryzicola-Induced Hypersensitive Response and Non-host Resistance in Tomato.
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Frontiers in plant science
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plant
| 1,000 | 57 |
Non-destructive assessment of plant nitrogen (N) status is essential for efficient crop production and N management in intensive rice ( Oryza sativa L.) cropping systems. Chlorophyll meter (SPAD-502) has been widely used as a rapid, non-destructive and cost-effective diagnostic tool for in-season assessment of crop N status. The present study was intended to establish the quantitative relationships between chlorophyll meters readings, plant N concentration (PNC), N nutrition index (NNI), accumulated N deficit (AND), and N requirement (NR), as well as to compare the stability of these relationships at different vegetative growth stages in Japonica and Indica rice cultivars. Seven multi-locational field experiments using varied N rates and seven rice cultivars were conducted in east China. The results showed that the PNC and chlorophyll meters readings increased with increasing N application rates across the cultivars, growing seasons, and sites. The PNC and chlorophyll meters readings under varied N rates ranged from 2.29 to 3.21, 1.06 to 1.82 and 37.10 to 45.4 and 37.30 to 46.6, respectively, at TL and HD stages for Japonica rice cultivars, while they ranged from 2.25 to 3.23, 1.34 to 1.91 and 35.6 to 43.3 and 37.3 to 45.5 for Indica rice cultivars, respectively. The quantitative relationships between chlorophyll meters readings, PNC, NNI, AND, and NR established at different crop growth stages in two rice ecotypes, were highly significant with R 2 values ranging from 0.69 to 0.93 and 0.71 to 0.86 for Japonica and Indica rice, respectively. The strongest relationships were observed for AND and NR at panicle initiation and booting stages in both rice ecotypes. The validation of the relationships developed in the present study with an independent data exhibited a solid model performance and confirmed their robustness as a reliable and rapid diagnostic tool for in-season estimation of plant N parameters for sustainable N management in rice. The results of this study will offer a suitable approach for managing N application precisely during the growth period of the rice crop in intensive rice cropping systems of east China.
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Non-destructive Assessment of Plant Nitrogen Parameters Using Leaf Chlorophyll Measurements in Rice.
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Frontiers in plant science
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plant
| 1,000 | 57 |
The MYB family is one of the largest families of transcription factors in plants. Although, some MYBs were reported to play roles in secondary metabolism, no comprehensive study of the MYB family in Chinese pear (Pyrus bretschneideri Rehd.) has been reported. In the present study, we performed genome-wide analysis of MYB genes in Chinese pear, designated as PbMYBs, including analyses of their phylogenic relationships, structures, chromosomal locations, promoter regions, GO annotations, and collinearity. A total of 129 PbMYB genes were identified in the pear genome and were divided into 31 subgroups based on phylogenetic analysis. These PbMYBs were unevenly distributed among 16 chromosomes (total of 17 chromosomes). The occurrence of gene duplication events indicated that whole-genome duplication and segmental duplication likely played key roles in expansion of the PbMYB gene family. Ka/Ks analysis suggested that the duplicated PbMYBs mainly experienced purifying selection with restrictive functional divergence after the duplication events. Interspecies microsynteny analysis revealed maximum orthology between pear and peach, followed by plum and strawberry. Subsequently, the expression patterns of 20 PbMYB genes that may be involved in lignin biosynthesis according to their phylogenetic relationships were examined throughout fruit development. Among the 20 genes examined, PbMYB25 and PbMYB52 exhibited expression patterns consistent with the typical variations in the lignin content previously reported. Moreover, sub-cellular localization analysis revealed that two proteins PbMYB25 and PbMYB52 were localized to the nucleus. All together, PbMYB25 and PbMYB52 were inferred to be candidate genes involved in the regulation of lignin biosynthesis during the development of pear fruit. This study provides useful information for further functional analysis of the MYB gene family in pear.
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MYB Transcription Factors in Chinese Pear (Pyrus bretschneideri Rehd.): Genome-Wide Identification, Classification, and Expression Profiling during Fruit Development.
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Frontiers in plant science
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plant
| 1,000 | 57 |
Phenology-the timing of life-history events-is a key trait for understanding responses of organisms to climate. The digitization and online mobilization of herbarium specimens is rapidly advancing our understanding of plant phenological response to climate and climatic change. The current practice of manually harvesting data from individual specimens, however, greatly restricts our ability to scale-up data collection. Recent investigations have demonstrated that machine-learning approaches can facilitate this effort. However, present attempts have focused largely on simplistic binary coding of reproductive phenology (e.g., presence/absence of flowers). Here, we use crowd-sourced phenological data of buds, flowers, and fruits from >3,000 specimens of six common wildflower species of the eastern United States ( Anemone canadensis L., A. hepatica L., A. quinquefolia L., Trillium erectum L., T. grandiflorum (Michx.) Salisb., and T. undulatum Wild.) to train models using Mask R-CNN to segment and count phenological features. A single global model was able to automate the binary coding of each of the three reproductive stages with >87% accuracy. We also successfully estimated the relative abundance of each reproductive structure on a specimen with ≥90% accuracy. Precise counting of features was also successful, but accuracy varied with phenological stage and taxon. Specifically, counting flowers was significantly less accurate than buds or fruits likely due to their morphological variability on pressed specimens. Moreover, our Mask R-CNN model provided more reliable data than non-expert crowd-sourcers but not botanical experts, highlighting the importance of high-quality human training data. Finally, we also demonstrated the transferability of our model to automated phenophase detection and counting of the three Trillium species, which have large and conspicuously-shaped reproductive organs. These results highlight the promise of our two-phase crowd-sourcing and machine-learning pipeline to segment and count reproductive features of herbarium specimens, thus providing high-quality data with which to investigate plant responses to ongoing climatic change.
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A New Method for Counting Reproductive Structures in Digitized Herbarium Specimens Using Mask R-CNN.
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Frontiers in plant science
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plant
| 1,000 | 57 |
Ozone (O 3 ) stress severely affects the normal growth of grape ( Vitis vinifera L.) leaves. Melatonin (MT) plays a significant role in plant response to various abiotic stresses, but its role in O 3 stress and related mechanisms are poorly understood. In order to understand the mechanism of MT in alleviate O 3 stress in grape leaves, we perform a transcriptome analyses of grapes leaves under O 3 stress with or without MT treatment. Transcriptome analysis showed that the processes of ethylene biosynthesis and signaling were clearly changed in "Cabernet Sauvignon" grapes under O 3 and MT treatment. O 3 stress induced the expression of genes related to ethylene biosynthesis and signal transduction, while MT treatment significantly inhibited the ethylene response mediated by O 3 stress. Further experiments showed that both MT and aminoethoxyvinylglycine (AVG, an inhibitor of ethylene biosynthesis) enhanced the photosynthetic and antioxidant capacities of grape leaves under O 3 stress, while ethephon inhibited those capacities. The combined treatment effect of MT and ethylene inhibitor was similar to that of MT alone. Exogenous MT reduced ethylene production in grape leaves under O 3 stress, while ethephon and ethylene inhibitors had little effect on the MT content of grape leaves after O 3 stress. However, overexpression of VvACO2 ( 1-aminocyclopropane-1-carboxylate oxidase2 ) in grape leaves endogenously induced ethylene accumulation and aggravated O 3 stress. Overexpression of the MT synthesis gene VvASMT1 ( acetylserotonin methyltransferase1 ) in tobacco ( Nicotiana tabacum L.) alleviated O 3 stress and reduced ethylene biosynthesis after O 3 stress. In summary, MT can alleviate O 3 stress in grape leaves by inhibiting ethylene biosynthesis.
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Melatonin Relieves Ozone Stress in Grape Leaves by Inhibiting Ethylene Biosynthesis.
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Frontiers in plant science
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plant
| 1,000 | 57 |
Citrus is one of the world's most important fruit crops, contributing essential nutrients, such as vitamin C and minerals, to the human diet. It is characterized by two important traits: first, its major edible part is composed of juice sacs, a unique structure among fruit, and second, relatively high levels of citric acid are accumulated in the vacuole of the juice sac cell. Although the major routes of primary metabolism are generally the same in citrus fruit and other plant systems, the fruit's unique structural features challenge our understanding of carbon flow into the fruit and its movement through all of its parts. In fact, acid metabolism and accumulation have only been summarized in a few reviews. Here we present a comprehensive view of sugar, acid and amino acid metabolism and their connections within the fruit, all in relation to the fruit's unique structure.
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Primary Metabolism in Citrus Fruit as Affected by Its Unique Structure.
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Frontiers in plant science
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plant
| 1,000 | 57 |
Aluminium stress causes plant growth retardation and engenders productivity loss under acidic soil conditions. This study accentuates morpho-physiological and molecular bases of aluminium (Al) tolerance within and between wild (ILWL-15) and cultivated (L-4602 and BM-4) lentil species. Morpho-physiological studies revealed better cyto-morphology of tolerant genotypes over sensitive under Al 3+ stress conditions. Mitotic lesions were observed in root cells under these conditions. Transcriptome analysis under Al 3+ stress revealed 30,158 specifically up-regulated genes in different comparison groups showing contigs between 15,305 and 18,861 bp. In tolerant genotypes, top up-regulated differentially expressed genes (DEGs) were found to be involved in organic acid synthesis and exudation, production of antioxidants, callose synthesis, protein degradation, and phytohormone- and calcium-mediated signalling under stress conditions. DEGs associated with epigenetic regulation and Al 3+ sequestration inside vacuole were specifically upregulated in wild and cultivars, respectively. Based on assembled unigenes, an average of 6,645.7 simple sequence repeats (SSRs) and 14,953.7 high-quality single nucleotide polymorphisms (SNPs) were spotted. By quantitative real-time polymerase chain reaction (qRT-PCR), 12 selected genes were validated. Gene ontology (GO) annotation revealed a total of 8,757 GO terms in three categories, viz ., molecular, biological, and cellular processes. Kyoto Encyclopaedia of Genes and Genomes pathway scanning also revealed another probable pathway pertaining to metacaspase-1,-4, and -9 for programmed cell death under Al-stress conditions. This investigation reveals key inter- and intraspecies metabolic pathways associated with Al-stress tolerance in lentil species that can be utilised in designing future breeding programmes to improve lentil and related species towards Al 3+ stress.
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Comparative Inter- and IntraSpecies Transcriptomics Revealed Key Differential Pathways Associated With Aluminium Stress Tolerance in Lentil.
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Frontiers in plant science
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plant
| 1,000 | 57 |
Heavy metal pollution is a serious global environmental problem as it adversely affects plant growth and genetic variation. It also alters the composition and activity of soil microbial communities. The objectives of this study were to determine the soil microbial diversity, bermudagrass genetic variation in Cd contaminated or uncontaminated soils from Hunan province of China, and to evaluate Cd-tolerance of bermudagrass at different soils. The Biolog method, hydroponic experiments and simple sequence repeat markers were used to assess the functional diversity of microorganisms, Cd-tolerance and the genetic diversity of bermudagrass, respectively. Four of the sampling sites were heavily contaminated with heavy metals. The total bioactivity, richness, and microbial diversity decreased with increasing concentration of heavy metal. The hydroponic experiment revealed that bermudagrass populations collected from polluted sites have evolved, encompassing the feature of a higher resistance to Cd toxicity. Higher genetic diversity was observed to be more in contaminated populations than in uncontaminated populations. Heavy metal pollution can result in adverse effects on plant growth, soil microbial diversity and activity, and apparently has a stronger impact on the genetic structure. The results of this study provide new insights and a background to produce a genetic description of populations in a species that is suitable for use in phytoremediation practices.
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Effect of Heavy Metals Pollution on Soil Microbial Diversity and Bermudagrass Genetic Variation.
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Frontiers in plant science
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plant
| 1,000 | 57 |
Water and nutrient acquisition is a critical function of plant root systems. Root system architecture (RSA) traits are often complex and controlled by many genes. This is the first genome-wide association study reporting genetic loci for RSA traits for field-grown soybean ( Glycine max ). A collection of 289 soybean genotypes was grown in three environments, root crowns were excavated, and 12 RSA traits assessed. The first two components of a principal component analysis of these 12 traits were used as additional aggregate traits for a total of 14 traits. Marker-trait association for RSA traits were identified using 31,807 single-nucleotide polymorphisms (SNPs) by a genome-wide association analysis. In total, 283 (non-unique) SNPs were significantly associated with one or more of the 14 root traits. Of these, 246 were unique SNPs and 215 SNPs were associated with a single root trait, while 26, four, and one SNPs were associated with two, three, and four root traits, respectively. The 246 SNPs marked 67 loci associated with at least one of the 14 root traits. Seventeen loci on 13 chromosomes were identified by SNPs associated with more than one root trait. Several genes with annotation related to processes that could affect root architecture were identified near these 67 loci. Additional follow-up studies will be needed to confirm the markers and candidate genes identified for RSA traits and to examine the importance of the different root characteristics for soybean productivity under a range of soil and environmental conditions.
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Genome-Wide Association Study of Topsoil Root System Architecture in Field-Grown Soybean [Glycine max (L.) Merr.].
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Frontiers in plant science
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plant
| 1,000 | 57 |
Rice is a crop feeding half of the world's population. With the continuous raise of yield potential via genetic improvement, rice breeding has entered an era where multiple genes conferring complex traits must be efficiently manipulated to increase rice yield further. Recurrent selection is a sound strategy for manipulating multiple genes and it has been successfully performed in allogamous crops. However, the difficulties in emasculation and hand pollination had obstructed efficient use of recurrent selection in autogamous rice. Here, we report development of the dwarf male-sterile rice that can facilitate recurrent selection in rice breeding. We adopted RNAi technology to synergistically regulate rice plant height and male fertility to create the dwarf male-sterile rice. The RNAi construct pTCK-EGGE, targeting the OsGA20ox2 and OsEAT1 genes, was constructed and used to transform rice via Agrobacterium -mediated transformation. The transgenic T0 plants showing largely reduced plant height and complete male-sterile phenotypes were designated as the dwarf male-sterile plants. Progenies of the dwarf male-sterile plants were obtained by pollinating them with pollens from the wild-type. In the T1 and T2 populations, half of the plants were still dwarf male-sterile; the other half displayed normal plant height and male fertility which were designated as tall and male-fertile plants. The tall and male-fertile plants are transgene-free and can be self-pollinated to generate new varieties. Since emasculation and hand pollination for dwarf male-sterile rice plants is no longer needed, the dwarf male-sterile rice can be used to perform recurrent selection in rice. A dwarf male-sterile rice-based recurrent selection model has been proposed.
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Engineered Dwarf Male-Sterile Rice: A Promising Genetic Tool for Facilitating Recurrent Selection in Rice.
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Frontiers in plant science
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plant
| 1,000 | 57 |
The biology of living organisms is determined by the action and interaction of a large number of individual gene products, each with specific functions. Discovering and annotating the function of gene products is key to our understanding of these organisms. Controlled experiments and bioinformatic predictions both contribute to functional gene annotation. For most species it is difficult to gain an overview of what portion of gene annotations are based on experiments and what portion represent predictions. Here, I survey the current state of experimental knowledge of enzymes and metabolism in Arabidopsis thaliana as well as eleven economically important crops and forestry trees - with a particular focus on reactions involving organic acids in central metabolism. I illustrate the limited availability of experimental data for functional annotation of enzymes in most of these species. Many enzymes involved in metabolism of citrate, malate, fumarate, lactate, and glycolate in crops and forestry trees have not been characterized. Furthermore, enzymes involved in key biosynthetic pathways which shape important traits in crops and forestry trees have not been characterized. I argue for the development of novel high-throughput platforms with which limited functional characterization of gene products can be performed quickly and relatively cheaply. I refer to this approach as systems-level experimental characterization. The data collected from such platforms would form a layer intermediate between bioinformatic gene function predictions and in-depth experimental studies of these functions. Such a data layer would greatly aid in the pursuit of understanding a multiplicity of biological processes in living organisms.
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Highlighting the Need for Systems-Level Experimental Characterization of Plant Metabolic Enzymes.
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Frontiers in plant science
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plant
| 1,000 | 57 |
Hybridization is key to the evolution and diversity of plants in nature. Nepenthaceae comprises a family of diverse tropical carnivorous pitcher plant species with extensive hybridization. However, there is no study to date on the metabolite expression of hybrids in this family. We performed a non-targeted metabolomics analysis of the pitchers of two Nepenthes species with different dietary habits, namely, the semi-detritivorous N. ampullaria and carnivorous N. rafflesiana with their hybrid ( N . × hookeriana ) for a comparative study. The whole-pitcher samples were extracted in methanol:chloroform:water (3:1:1) via sonication-assisted extraction and analyzed using ultra-performance liquid chromatography time-of-flight mass spectrometry (UPLC-TOF-MS) followed by data analysis to profile chemical compositions. A total of 1,441 metabolite features were profiled from the three species in which 43.3% of features in the hybrid samples were not found in either of its parents. The partial least squares discriminant analysis (PLS-DA) found 324 metabolite features with variable in projection (VIP) values greater than one in which 55 features were statistically significant. This showed that the hybrid is closer to N . rafflesiana , which is consistent to the previous study on gene and protein expressions. A total of 105 metabolites were putatively identified with manual searches using public metabolite databases. Phenols were detected to be the most abundant secondary metabolites due to a high flavonoid content, especially in N. rafflesiana . The most abundant feature 476.3s:449.102 was found to be the most significant VIP for distinguishing between the three species as a chemical marker. This is the first study comparing metabolites in the carnivory organs of different Nepenthes species with comprehensive profiling and putative identification. The differential metabolite compositions in the pitchers of different species might have ecological implications with the hybrid showing intermediate phenotype between the parents as well as manifesting unique metabolites. However, there is no clear evidence of metabolites related to the differences in dietary habits between the hybrid and the two parent species.
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UPLC-TOF-MS/MS-Based Metabolomics Analysis Reveals Species-Specific Metabolite Compositions in Pitchers of Nepenthes ampullaria, Nepenthes rafflesiana, and Their Hybrid Nepenthes × hookeriana.
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Frontiers in plant science
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plant
| 1,000 | 57 |
Fruit ripening is a physiologically complex process altering texture, color, flavor, nutritional value, and aroma. However, some fruits are consumed at an early stage of ripening due to the very peculiar characteristics varying during ripening. An example is a particular ecotype of pepper, the Friariello pepper, among the most important representatives of Campania (Southern Italy) agro-alimentary culture. In this study, for the first time, the physiological variations during Friariello ripening (green, veraison, and fully ripe) were evaluated by hyphenated mass spectrometric techniques in a proteomic and metabolomic approach. We found that Lutein and Thaumatin are particularly abundant in the green Friariello. Friariello at an early stage of ripening, is rich in volatile compounds like butanol, 1 3 5-cycloheptatriene, dimethylheptane, α-pinene, furan-2-penthyl, ethylhexanol, 3-carene, detected by gas chromatography-mass spectrometry (GC-MS) analysis, which give it the peculiar fresh and pleasant taste. The detected features of Friariello may justify its preferential consumption in the early ripening stage and outline new knowledge aimed at preserving specific agro-cultural heritage.
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Why Consumers Prefer Green Friariello Pepper: Changes in the Protein and Metabolite Profiles Along the Ripening.
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Frontiers in plant science
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plant
| 1,000 | 57 |
Ataxia-telangiectasia mutated (ATM) is a serine-threonine kinase that is integral in the response to DNA double-stranded breaks (DSBs). Cells and tissues lacking ATM are prone to tumor development and enhanced tumor cell migration and invasion. Interestingly, ATM-deficient cells exhibit high levels of oxidative stress; however, the direct mechanism whereby ATM-associated oxidative stress may contribute to the cancer phenotype remains largely unexplored. Rac1, a member of the Rho family of GTPases, also plays an important regulatory role in cellular growth, motility, and cancer formation. Rac1 can be activated directly by reactive oxygen species (ROS), by a mechanism distinct from canonical guanine nucleotide exchange factor-driven activation. Here we show that loss of ATM kinase activity elevates intracellular ROS, leading to Rac1 activation. Rac1 activity drives cytoskeletal rearrangements resulting in increased cellular spreading and motility. Rac1 siRNA or treatment with the ROS scavenger N-Acetyl-L-cysteine restores wild-type migration. These studies demonstrate a novel mechanism whereby ATM activity and ROS generation regulates Rac1 to modulate pro-migratory cellular behavior.
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Loss of ATM positively regulates Rac1 activity and cellular migration through oxidative stress.
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Biochemical and biophysical research communications
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physics
| 361 | 56 |
Di-2-pyridylketone-4,4-dimethyl-3-thiosemicarbazone (Dp44mT), as the novel iron chelator, has been reported to inhibit the tumorigenesis and progression of various cancer cells. However, whether Dp44mT has anticancer effects in colon cancer cells is still unknown. Here, we investigated the antitumor action of Dp44mT in colon cancer and its underlying mechanisms, and the connections between Dp44mT and N-myc downstream-regulated genes 1(Ndrg1). We used cell viability, migration and invasion assay, flow cytometry, western blot and qRT-PCR to examine the anticancer effects of Dp44mT and Ndrg1. We found that Dp44mT suppressed cell viability, migration, invasion and induced apoptosis of colon cancer cells and over-expression of Ndrg1 also suppressed cell viability, migration, invasion and induced apoptosis of colon cancer cells. Dp44mT attenuated the TGF-β1-induced EMT in colon cancer cells, and Dp44mT could up-regulate Ndrg1 expression level. Overexpression of Ndrg1 attenuates the TGF-β1-induced EMT, Dp44mT and Ndrg1 suppressed EMT through activation of Wnt/β catenin signaling pathway. In conclusion, our data demonstrated that Dp44mT/Ndrg1 have effective anticancer capability in colon cancer cells and that may represent a promising treatment strategy for human colon cancer.
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Iron chelator-induced up-regulation of Ndrg1 inhibits proliferation and EMT process by targeting Wnt/β-catenin pathway in colon cancer cells.
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Biochemical and biophysical research communications
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physics
| 361 | 56 |
Fulvestrant is the FDA-approved "pure anti-estrogen" agent for malignant breast cancer therapy. But endocrine resistance causes drug failure. A new approach is desired for fulvestrant-resistant breast cancer (FRBC) therapy. This study aims to find an effective approach to inhibit FRBC for patients with advanced breast cancer. MTT assay was first performed to detect the effect of inhibitors of c-ABL (imatinib) and EGFR (lapatinib) on FRBC cells. Microarray analysis was carried out to identify microRNA which is significantly changed between parental and FRBC cells. The related mechanisms were analyzed by qRT-PCR, MTT, AO staining and western blotting. Dual treatment significantly inhibited cell growth of FRBC and upregulated microRNA-375 (miR-375). Overexpression of miR-375 inhibited growth of FRBC cells, reduced autophagy, and decreased expression of ATG7 and LC3-II. Dual treatment elevated expression of miR-375 more than any single one of these two inhibitors. Overexpression of miR-375 increased cell growth inhibition induced by dual treatment, and the effect was attenuated when miR-375 was inhibited. In conclusion, we identified that combined inhibition of EGFR and c-ABL can suppress the growth of FRBC cells and elucidated a mechanism within FRBC cells involving regulation of miR-375 and autophagy. Dual treatment may be useful for inhibiting fulvestrant-resistant breast cancer.
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Combined inhibition of EGFR and c-ABL suppresses the growth of fulvestrant-resistant breast cancer cells through miR-375-autophagy axis.
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Biochemical and biophysical research communications
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physics
| 361 | 56 |
Adipose tissue stem cells (ATSCs) are considered as a promising source in the field of cell therapy and regenerative medicine. In addition to direct cell replacement using stem cells, intercellular molecule exchange by stem cell secretory factors showed beneficial effects by reducing tissue damage and augmentation of endogenous repair. Delayed cutaneous wound healing is implicated in many conditions such as diabetes, aging, stress and alcohol consumption. However, the effects of cell-free extract of ATSCs (ATSC-Ex) containing secretome on wound healing process have not been investigated. In this study, ATSC-Ex was topically applied on the cutaneous wound and healing speed was examined. As a result, wound closure was much faster in the cell-free extract treated wound than control wound at 4, 6, 8 days after application of ATSC-Ex. Dermal fibroblast proliferation, migration and extracellular matrix (ECM) production are critical aspects of wound healing, and the effects of ATSC-Ex on human dermal fibroblast (HDF) was examined. ATSC-Ex augmented HDF proliferation in a dose-dependent manner and migration ability was enhanced by extract treatment. Representative ECM proteins, collagen type I and matrix metalloproteinase-1, are significantly up-regulated by treatment of ATSC-Ex. Our results suggest that the ATSC-Ex have improving effect of wound healing and can be the potential therapeutic candidate for cutaneous wound healing.
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Wound healing potential of adipose tissue stem cell extract.
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Biochemical and biophysical research communications
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physics
| 361 | 56 |
Epicardial progenitor cells (EpiCs) have a crucial role in cardiac development and vasculature formation. Here we detected the expression of Angiotensin II (Ang II) receptors AT1 and AT2 on EpiCs and demonstrated that AngII could increase the expression of smooth muscle specific markers, including α-smooth muscle actin (α-SMA) and myosin heavy chain 11 (Myh11) in EpiCs. Moreover, the expression of α-SMA and Myh11 induced by Ang II was blocked by pretreatment of EpiCs with the AT1 receptor antagonist losartan, but not the AT2 receptor antagonist PD123319. We further showed that the AngII-induced cells showed significant contractile responses to carbachol. These results implied that AngII could effectively induce EpiCs to differentiate into vascular smooth muscle-like cells through the AT1 receptor.
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Angiotensin Ⅱ induces the differentiation of mouse epicardial progenitor cells into vascular smooth muscle-like cells.
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Biochemical and biophysical research communications
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physics
| 361 | 56 |
CD97/ADGRE5, an adhesion G protein-coupled receptor (aGPCR), is highly expressed in several tumor cell types. CD97 has been shown to modulate tumorigenesis in part by promoting HUVEC migration, invasion and angiogenesis through the interaction with integrin α5β1 via its ectodomain RGD motif. In this study, we show that CD97 could induce angiogenesis via an alternative RGD-independent mechanism. Overexpression of CD97 with the wild-type or mutant RGD motif in HT1080 cells led to up-regulated MMP-9 and induced angiogenesis as revealed by the in vitro endothelial cell tube formation assay and in ovo chick chorioallantoic membrane assay. By contrast, expression of EMR2/ADGRE2, the CD97-homologous aGPCR that contains a corresponding SGD sequence, fails to induce angiogenesis due to lower MMP-9 expression. Interestingly, a single change of the SGD to RGD sequence allowed EMR2 to up-regulate MMP-9 expression, leading to enhanced angiogenesis. MMP-9 was shown to promote the proliferation, migration, and invasion of HUVEC partly by modulating the levels of VEGF, PIGF, and bFGF. Finally, we showed that the MMP-9 expression was in turn modulated by N-cadherin that was up-regulated by CD97 and EMR2/RGD. Our results indicate that two homologous aGPCRs, CD97 and EMR2, modulate angiogenesis and HUVEC proliferation, migration, and invasion through N-cadherin-regulated MMP-9 expression by RGD-independent and -dependent mechanisms, respectively.
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The role of the RGD motif in CD97/ADGRE5-and EMR2/ADGRE2-modulated tumor angiogenesis.
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Biochemical and biophysical research communications
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physics
| 361 | 56 |
The endoplasmic reticulum (ER) is a major site for protein synthesis, folding and transport, lipid and steroid synthesis, regulating redox potential, as well as calcium storage. It therefore relies on delicate homeostasis, and perturbation of the ER function and induction of ER stress can lead to apoptosis. One cause of disruption of the ER homeostasis is the accumulation of misfolded proteins. To prevent this perturbation, the Endoplasmic Reticulum-Associated Degradation (ERAD) quality control machinery is recruited to remove these proteins in a three-step process: (1) extraction from the ER, (2) ubiquitination, and (3) subsequent proteasomal degradation. However, the identity of the proteins regulated by the proteasome following induction of the ER stress has remained obscure. In the present study, we investigated the role of the proteasome in the modulation of the proteome of HeLa cells after treatment with thapsigargin and tunicamycin, two drugs known to induce ER stress through accumulation of misfolded proteins. Using label-free quantitative proteomics we found that out of the proteins identified to decrease in their level following induction of ER stress, more than 64% are targeted by the proteasome. Among these proteins, key players of the Wnt signaling pathway, such as β-catenin and GSK3, as well as α-catenin which is involved in cell-cell adhesion, were identified as being modulated by the proteasome upon ER stress.
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Identification of proteins regulated by the proteasome following induction of endoplasmic reticulum stress.
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Biochemical and biophysical research communications
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physics
| 361 | 56 |
Laboratory of genetics and physiology 2 (LGP2) and melanoma differentiation-associated gene 5 (MDA5) cooperatively detect viral RNA in the cytoplasm of Cardiovirus-infected cells and activate innate immune responses. Here, we evaluated whether the double-stranded RNA-binding protein PACT plays a role in this anti-viral response to further elucidate the mechanism. Immunoprecipitation experiments demonstrated that PACT interacts with LGP2 and that this interaction is enhanced by encephalomyocarditis virus (EMCV) infection. In vitro interaction analyses using purified recombinant proteins confirmed that the single-stranded Theiler's murine encephalitis virus genome enhanced the interaction between LGP2 and PACT. Small interfering RNA knockdown experiments further indicated that PACT is required for Cardiovirus-triggered interferon responses. To support this functional interaction with LGP2, overexpressed PACT was shown to enhance EMCV-triggered interferon promoter activity only when LGP2 and MDA5 were co-expressed but not when MDA5 is expressed alone. Together, our findings indicate a possible role of PACT in regulating the Cardiovirus-triggered immune responses mediated by MDA5 and LGP2, which opens the door to novel therapeutic strategies in interferon-related autoimmune diseases and cancer.
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PACT is required for MDA5-mediated immunoresponses triggered by Cardiovirus infection via interaction with LGP2.
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Biochemical and biophysical research communications
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physics
| 361 | 56 |
A major problem in the cancer treatment is the inherent resistance to chemotherapy. Identifying proteins that, once introduced in cancer cells, lead to a decreased efficiency of treatment outcome constitutes a major goal for biomedical research and applications. Survivin is a protein of IAPs family which its high expression can be a potential candidate for regulating cell death and survival in cancer therapy. To investigate the association of survivin increment and resistance to drug, survivin-reconstituted HEK (HEK-S) and HEK cells were used as in vitro models for the doxorubicin and docetaxel cellular response. Both morphological observation and survival assay exhibited that survivin reconstitution cells were significantly resistant to apoptotic stimuli by both drugs. It was observed that survivin overexpression has led to a decrease in caspase 3/7 activity and ROS level of cells but an increase in ATP content. Also, survivin-reconstituted cell displayed less red fluorescence compared to control after stimulation by drugs. Moreover, wound healing assay showed the ability of survivin to cause neighbouring cells to increase resistance to induction. These findings demonstrated survivin could be a potential target that can be inhibited the function of different drugs with various mechanisms in chemotherapy.
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Effects of doxorubicin and docetaxel on susceptibility to apoptosis in high expression level of survivin in HEK and HEK-S cell lines as in vitro models.
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Biochemical and biophysical research communications
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physics
| 361 | 56 |
A few decades ago, researchers found emerging evidence showing that a number of sequential events lead to the pathological cascade of Alzheimer's disease (AD) which is caused by the accumulation of amyloid beta (Aβ), a physiological peptide, in the brain. Therefore, regulation of Aβ represents a crucial treatment approach for AD. Neprilysin (NEP), a membrane metallo-endopeptidase, is a rate-limiting peptidase which is known to degrade the amyloid beta peptide. This study investigated soluble NEP (sNEP) produced by recombinant mammalian cells stably transfected with a non-viral NEP expression vector to demonstrate its protective effect against Aβ peptides in neuronal cells in vitro. Stably transfected HEK 293 cells were used to purify the soluble protein. sNEP and Aβ peptide co-treated hippocampal cells had a decreased level of Aβ peptides shown by an increase in cell viability and decrease in apoptosis measured by the CCK-8 and relative caspase-3 activity ratio assays, respectively. This study shows that stably transfected mammalian cells can produce soluble NEP proteins which could be used to protect against Aβ accumulation in AD and subsequently neuronal toxicity. Additionally, approaches using protein therapy for potential targets could change the pathological cascade of Alzheimer's disease.
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Protective effect of recombinant soluble neprilysin against β-amyloid induced neurotoxicity.
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Biochemical and biophysical research communications
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physics
| 361 | 56 |
Advanced colon cancer is extremely difficult to cure, underscoring the need to develop novel therapeutic agents. Prenylated curcumins that are semisynthetic curcumin derivatives with significant anti-cancer potential have been studied herein to assess their therapeutic potential for colon cancer and tested to this aim in vitro for their growth inhibitory properties against 5-fluorouracil + oxaliplatin resistant human colon cancer CR-HT29 and HCT-116 cells. The resulting most active product, gercumin (mono-O-geranylcurcumin), has been further tested for its synergistic effects with FOLFOX (a combination of 5-fluorouracil and oxaliplatin) on the same cell lines. Activity of this combination on colonosphere formation was also investigated. Gercumin was able to suppress the growth of cancer cells with a potency similar to that of curcumin. A synergistic effect of this compound and FOLFOX was also observed. doses tested for synergy in the colonosphere assays did not show greater suppression of colonosphere formation than independent treatment with either reagent alone. Only one of the combinations was shown to be more effective at suppressing colonosphere formation [gercumin 5 μM + FOLFOX (2x)]. Thus, the growth inhibitory effects of curcumin against human cancer cells can be modulated and enhanced by the introduction of hydrophobic chains, normally found in several natural compounds, like the geranyl one. Such compounds are also able to synergize with known chemotherapeutics.
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Gercumin synergizes the action of 5-fluorouracil and oxaliplatin against chemoresistant human cancer colon cells.
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Biochemical and biophysical research communications
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physics
| 361 | 56 |
Liraglutide, a glucagon-like peptide-1 (GLP-1) analogue, is an antidiabetic drug. It has been shown to improve endothelial dysfunction, but the mechanism remains somewhat unclear. Leptin can also improve endothelial function. Cardiovascular disease (CVD) is linked to hyperleptinemia, and leptin resistance, how liraglutide influences the effect of leptin on endothelial function, is never reported. We used palmitic acid (PA) to mimic hyperlipidemia in endothelial cells to explore the cardio-protective mechanism of liraglutide and its impact on the role of leptin. Human umbilical vein endothelial cells (HUVECs) were incubated with PA for 16 h and then were treated with liraglutide for 30 min. PA elevated not only phosphorylation of JNK and IKKα/β, but also the expression of IL-6 in HUVECs. These effects of PA were reversed by liraglutide. In addition, liraglutide increased phosphorylation of eNOS, AMPK, and the release of NO but had no effect on PKC phosphorylation. In addition, leptin elevated eNOS phosphorylation but was abrogated by PA. However, in the presence of liraglutide, leptin regained its function of elevating eNOS phosphorylation. Last, we found that liraglutide inhibited PA-elevated SOCS3, which is a marker of leptin resistance. GLP-1 impairs endothelial inflammatory signals, improves endothelial function, and reverses leptin resistance.
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Liraglutide ameliorates palmitate-induced endothelial dysfunction through activating AMPK and reversing leptin resistance.
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Biochemical and biophysical research communications
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physics
| 361 | 56 |
A failure of bone marrow mesenchymal stem cells (BM-MSCs) to adhere to hematopoietic cells is an essential cause of the progression of chronic myelogenous leukemia and is also a cause of failure of bone marrow (BM) transplantation, but the exact mechanisms of this have not been fully elucidated. Recent studies have indicated that microRNAs (miRNAs) are contained in leukemia-derived exosomes and are involved in modulating the BM microenvironment. In this study, we found that K562 cell-derived exosomes transfer miR-711 to BM-MSCs and suppress the adhesive function of BM-MSCs. Using qRT-PCR, we also confirmed a significantly higher level of miR-711 in exosomes derived from K562 cells than in exosomes derived from parental cells. The BM-MSCs co-cultured with exosomes derived from K562 cells showed a lower adhesion rate than did controls. We further demonstrated that exosomal transfer of miR-711 induced decreased adhesive abilities by inhibiting expression of adhesion molecule CD44 in BM-MSCs. In conclusion, our study reveals that K562 cell-derived exosomal miR-711 can be transferred to BM-MSCs and weaken adhesive abilities by silencing the expression of the adhesion molecule CD44.
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K562 cell-derived exosomes suppress the adhesive function of bone marrow mesenchymal stem cells via delivery of miR-711.
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Biochemical and biophysical research communications
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physics
| 361 | 56 |
Heated tobacco products (HTPs) are an emerging class of tobacco goods that claim to have lower health risks than those of smoking combustible tobacco products. In this study, we exposed human lung epithelial cell lines to extracts prepared from HTP aerosols and combustible cigarette smoke to compare cytotoxicity. We focused on the effects of aldehydes present in the aerosols of HTPs at levels close to those in combustible cigarette smoke. Significant toxicity was confirmed for the HTP extract, albeit to a lesser extent than that with the combustible cigarette extract. When redox balance was evaluated by the oxidative loss of low-molecular-weight thiols in the cells, we found that total glutathione (GSH) contents and low-molecular-weight thiol levels were significantly decreased after exposure to the aerosol extract of HTPs. These results indicated that GSH is rapidly consumed during the detoxification of xenobiotics, such as aldehydes from tobacco extracts. Accordingly, exposure to the aerosol extract of HTPs resulted in the enhanced carbonylation of many proteins. In a simple comparison, the results for HTPs were significantly different from those obtained with combustible cigarette smoke, suggesting reduced toxicity of HTPs. However, we found significant and harmful effects after exposing lung epithelial cells to the aerosol extract of HTPs. Thus, a further comprehensive study is needed to clarify the lung damage induced via the long-term inhalation of aerosols from HTPs.
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Exposure to aerosol extract from heated tobacco products causes a drastic decrease of glutathione and protein carbonylation in human lung epithelial cells.
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Biochemical and biophysical research communications
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physics
| 361 | 56 |
Adult mammalian cardiomyocytes have extremely limited capacity to regenerate, and it is believed that a strong intrinsic mechanism is prohibiting the cardiomyocytes from entering the cell cycle. microRNAs that promote proliferation in cardiomyocyte can be used as probes to identify novel genes suppressing cardiomyocytes proliferation, thus dissecting the mechanism(s) preventing cardiomyocytes from duplication. In particular, miR-199a-3p has been found as a potent activator of proliferation in rodent cardiomyocyte, although its molecular targets remain elusive. Here, we identified Cd151 as a direct target of miR-199a-3p, and its expression is greatly suppressed by miR-199a-3p. Cd151 gain-of-function reduced cardiomyocyte proliferation, conversely Cd151 loss-of-function increased cardiomyocytes proliferation. Overexpression of Cd151 blocks the activating effect of miR-199a-3p on cardiomyocyte proliferation, suggesting Cd151 is a functional target of miR-199a-3p in cardiomyocytes. Mechanistically, we found that Cd151 induces p38 expression, a known negative regulator of cardiomyocyte proliferation, and pharmacological inhibition of p38 rescued the inhibitory effect of Cd151 on proliferation. Together, this work proposes Cd151 as a novel suppressor of cardiomyocyte proliferation, which may provide a new molecular target for developing therapies to promote cardiac regeneration.
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miR-199a-3p promotes cardiomyocyte proliferation by inhibiting Cd151 expression.
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Biochemical and biophysical research communications
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physics
| 361 | 56 |
Circular RNAs (circRNAs) is a novel type of non-coding RNAs generated from back splicing, which has been verified to mediate multiple tumorigenesis. However, the role of circRNA in osteosarcoma is still unclear. In the present study, we preliminarily screened the circRNAs expression profiles in osteosarcoma and investigated the potential regulation mechanism. The circRNAs expression profiles in osteosarcoma were screened using circRNA microarray analysis, and results showed that there were 1152 circRNAs up-regulated and 915 circRNAs down-regulated in tumor tissue compared to adjacent tissue. Hsa_circ_0001564, located at 5q35.3 and its associated-gene symbol is CANX, was one of the significantly overexpressed circRNAs in osteosarcoma tissue, as well as in osteosarcoma cell lines. In functional experiments, hsa_circ_001564 knockdown significantly suppressed the proliferation activity, induced cell cycle arrest in G0/G1 phase, and promoted apoptosis in HOS and MG-63 cells. Subsequently, we explored the probable mechanism of hsa_circ_001564, and fortunately, bioinformatics analysis revealed that miR-29c-3p contained the complementary binding region with hsa_circ_0001564, which was confirmed by dual-luciferase reporter assay. Moreover, rescue experiments illustrated that miR-29c-3p could reverse the oncogenesis effect of hsa_circ_001564. Our study discovers that hsa_circ_0001564 acts as miR-29c-3p sponge to mediate the tumorigenicity, which could act as a potential biomarker for the osteosarcoma and provide a novel insight for competing endogenous RNAs (ceRNAs) mechanism in osteosarcoma.
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Circular RNA hsa_circ_0001564 regulates osteosarcoma proliferation and apoptosis by acting miRNA sponge.
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Biochemical and biophysical research communications
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physics
| 361 | 56 |
Ribavirin is an anti-viral drug but has recently gained attention as a potential candidate for cancer treatment. In line with these efforts, our work is the first to demonstrate that ribavirin, at clinically relevant concentration, selectively targets pediatric osteosarcoma and increases chemosensitivity. Using preclinical osteosarcoma cell and xenograft models, we found that ribavirin is active against osteosarcoma bulk and subpopulations with highly proliferative and invasive properties via inhibiting growth, inducing apoptosis and suppressing colony formation. At the same concentrations, ribavirin either did not or affected human normal osteoblastic cell and fibroblast cells in a less extent than osteosarcoma cells. Notably, the combination of ribavirin with doxorubicin resulted in greater efficacy than single drug alone. The combination completely arrested the osteosarcoma growth in vivo throughout the whole duration of drug treatment. We further showed that ribavirin acted on osteosarcoma largely via targeting eIF4E. In addition to eIF4E, ribavirin also modulated phosphorylation of Erk and expression of EZH2 and Snail without affecting Akt and mTOR. Lastly, we found that eIF4E expression and phosphorylation were elevated in osteosarcoma compared to normal cells, which might explain the selective anti-osteosarcoma activity of ribavirin. eIF4E depletion mimics the inhibitory effects of ribavirin, further confirm that eIF4E is the essential target of ribavirin in osteosarcoma. Our work provides fundamental evidence of repurposing ribavirin for the treatment of osteosarcoma. Our findings also highlight the therapeutic value of inhibiting eIF4E in osteosarcoma.
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Clinically relevant concentration of anti-viral drug ribavirin selectively targets pediatric osteosarcoma and increases chemosensitivity.
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Biochemical and biophysical research communications
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physics
| 361 | 56 |
Non-alcoholic fatty liver disease (NAFLD) is the most common liver disorder with intricate etiology. It is closely associated with metabolic syndrome, insulin resistance and endoplasmic reticulum (ER) stress. Exostosin1 (Ext1) is an ER-resident transmembrane glycosyltransferase, which plays an important role in ER homeostasis. Loss-of-function mutations in Ext1 link to hereditary multiple exostosis (HME). The present research was undertaken to identify the effect of Ext1 in the progress of NAFLD. High-fat-diet induced mice obesity, hepatic steatosis and decreased hepatic Ext1 expression. In consistent with evaluation of NAFLD mice possessing down-regulated Ext1 expression, free fatty acid (FFA) treatment blunted Ext1 expression in hepatocytes. In human subjects, HME patients presented elevated fasting blood glucose-one of the criteria that define insulin resistance. In vitro experiments, Ext1 deficiency promoted FFA-induced insulin resistance in hepatocytes by analysis of glycogen storage and hallmarks of gluconeogenesis, ascertaining its association with insulin resistance. Mechanically, Ext1 silencing exacerbated ER stress triggered by FFA, which severely disrupted autophagy in hepatocytes, and thereby accelerated the progression of NAFLD. In conclusion, our study demonstrates a beneficial role for Ext1 during the development of NAFLD, which establishes a novel correlation between Ext1 and ER stress-induced perturbations of autophagy during NAFLD progression.
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Obesity induced Ext1 reduction mediates the occurrence of NAFLD.
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Biochemical and biophysical research communications
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physics
| 361 | 56 |
B-cell CLL/lymphoma 6 (BCL6) is a transcriptional master regulator that can repress more than 1200 potential target genes. It exerts oncogenic effects through the inhibition of differentiation, DNA damage sensing and apoptosis in several human hematopoietic malignancies, including multiple myeloma (MM). The multifunctional cytokine interferon γ (IFNγ) exerts pro-apoptotic and anti-proliferative effects on MM cells in vitro, at least partially through the inhibition of the effects of interleukin 6 (IL6), one of the most important growth factor of MM and a strong inducer of BCL6 expression. However, IFNγ was also reported to directly upregulate BCL6 in several cell types. These observations prompted us to analyze the effect of IFNγ on BCL6 expression in MM cells. We discovered that among several myeloma growth/survival factors tested (including IL6, oncostatin M, insulin-like growth factor 1, tumor necrosis factor α and IFNα) IFNγ was the strongest inducer of BCL6 mRNA and protein expression in MM cell lines. IFNγ induced upregulation of BCL6 was dependent on the classical STAT1 signaling pathway, and affected both major BCL6 variants. Interestingly, although IFNα induced stronger STAT1 phosphorylation than IFNγ, it only slightly upregulated BCL6 in MM lines. We proved that IFNα induced BCL6 upregulation was limited by the concomitant activation of STAT5 signaling. We assume that BCL6 upregulation may represent a potentially pro-tumorigenic effect of IFNγ signaling in MM cells.
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Interferon γ is a strong, STAT1-dependent direct inducer of BCL6 expression in multiple myeloma cells.
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Biochemical and biophysical research communications
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physics
| 361 | 56 |
The development and design of highly active and stable electrocatalysts based on cheap and Earth-abundant materials is critically important to enable water splitting as a desirable renewable energy source. Herein, we fulfill the significant electrochemical water splitting enhancement in both electrocatalytic activity and durability by constructing self-supported nickel-cobalt nanowire catalysts with abundant oxygen vacancies. Specifically, the rich oxygen vacancies can largely promote the oxygen evolution reaction (OER) activity of optimal Ni 1 Co 1 O 2 NWs with a relatively low overpotential of 248 mV to drive a current density of 10 mA cm -2 . More significantly, after the phosphorization of Ni 1 Co 1 O 2 NWs, the resultant Ni 1 Co 1 P NWs can also display excellent electrocatalytic hydrogen evolution reaction (HER) performances with an overpotential of only 101 mV to achieve a current density of 10 mA cm -2 . Furthermore, benefiting from the unique 1D nanowire structure, the synergistic effect, and the optimal Gibbs free energy for hydrogen evolution evolved from the phosphorization, the Ni 1 Co 1 O 2 NWs//Ni 1 Co 1 P NWs couple is thus highly active and stable for overall water electrolysis with a low voltage of 1.58 V at 10 mA cm -2 , showing extraordinary promise for practical overall water splitting electrolysis.
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Self-supported nickel-cobalt nanowires as highly efficient and stable electrocatalysts for overall water splitting.
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Nanoscale
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engineering
| 1,895 | 26 |
Coupling of the electron orbital motion and spin, i.e., spin-orbit coupling (SOC) leads to nontrivial changes in energy-level structures, giving rise to various spectroscopies and applications. The SOC in solids generates energy-band inversion or splitting under zero or weak magnetic fields, which is required for topological phases or Majorana fermions. Here, we examined the interplay between the Zeeman splitting and SOC by performing the transport spectroscopy of Landau levels (LLs) in indium arsenide nanowires under a strong magnetic field. We observed the anomalous Zeeman splitting of LLs, which depends on the quantum number of LLs as well as the electron spin. We considered that this observation was attributed to the interplay between the Zeeman splitting and the SOC. Our findings suggest an approach of generating spin-resolved chiral electron transport in nanowires.
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The interplay between Zeeman splitting and spin-orbit coupling in InAs nanowires.
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Nanoscale
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engineering
| 1,895 | 26 |
An ultra-sensitive THz metasensor is presented based on quasi-BIC Fano resonance, which can distinguish extremely dilute concentrations (nM) of solutions. It provides a nondestructive sensing approach for disease prevention and diagnosis. However, the main drawback limiting the performance of THz-based bio-chemical sensors is the weak interaction between the optical field and the analyte, the characteristic scale of which is mismatched with the THz wavelength, leading to low sensitivity. Herein, we present an ultra-sensitive THz metasensor based on an electric Fano resonant metasurface which consists of three gold microrods arranged periodically. The designed electric Fano resonance provides a strong near-field enhancement near the surface of the microstructure, significantly boosting the light-analyte interactions and thus the sensitivity. Such an electric Fano resonance is formed by the interference between a leaky electric dipole resonance and a bound toroidal dipole mode which is a symmetry-protected bound state in the continuum supported by the sub-diffractive periodic system here. Owing to the strong electric fields generated near the interface of our microstructure around the toroidal dipole BIC, the proposed structure can distinguish extremely dilute concentrations (nM) of solutions. Importantly, by controlling the degree of geometrical asymmetry, the BIC-inspired mechanism provides an important and simple tool to engineer and tailor the linewidth and Q -factor of our proposed electric Fano resonance, indicating the ability to realize different biosensors for different optical regimes. Our results open new possibilities to realize a non-destructive and non-contact quantitative inspection of low-concentration solutions, providing a useful sensing approach for disease prevention and diagnosis.
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Electric Fano resonance-based terahertz metasensors.
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Nanoscale
|
engineering
| 1,895 | 26 |
For substantially promoting the unexpected rechargeable capability induced from the dissolution of Sb 2 Se 3 positive electrode materials in aluminum batteries, here a novel prototype of a cell assembled by a hybrid of single-crystalline Sb 2 Se 3 nanorods and N-doped reduced graphene oxide (SNG) coupled with a modified separator has been developed. With this specific cell design, the hybrid positive electrode material exhibits a high discharge potential (∼1.8 V) with a considerably high initial discharge capacity of up to 343 mA h g -1 at a current density of 500 mA g -1 . Owing to the alleviation of active material loss from the positive electrode, the cell having the modified separator exhibits much enhanced cycling stability. Besides, nitrogen-doping on the reduced graphene oxide is found to boost the active sites in SNG, and thus the cycling performance has been largely improved. The strategy used in this work offers a universal plateau for designing long-life cycle aluminum batteries.
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Sb2Se3 nanorods with N-doped reduced graphene oxide hybrids as high-capacity positive electrode materials for rechargeable aluminum batteries.
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Nanoscale
|
engineering
| 1,895 | 26 |
Lead-free piezoelectric 0.5(Ba 0.7 Ca 0.3 )TiO 3 -0.5Ba(Zr 0.2 Ti 0.8 )O 3 (BCTZ) nanoparticles (NPs) composed of earth-abundant elements were adopted for use in a flexible composite-based piezoelectric energy harvester (PEH) that can convert mechanical deformation into electrical energy. The solid-state synthesized BCTZ NPs and silver nanowires (Ag NWs) chosen to reduce the toxicity of the filler materials were blended with a polydimethylsiloxane (PDMS) matrix to produce a piezoelectric nanocomposite (p-NC). The naturally flexible polymer-based p-NC layers were sandwiched between two conductive polyethylene terephthalate plastic substrates to achieve a flexible energy harvester. The BCTZ NP-based PEH effectively generated an output voltage peak of ∼15 V and a current signal of ∼0.8 μA without time-dependent degradation. This output was adequate to operate a liquid crystal display (LCD) and to turn on six blue light emitting diodes (LEDs).
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A flexible energy harvester based on a lead-free and piezoelectric BCTZ nanoparticle-polymer composite.
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Nanoscale
|
engineering
| 1,895 | 26 |
We introduce a two-channel microfluidic atomic force microscopy (AFM) cantilever that combines the nanomechanical sensing functionality of an AFM cantilever with the ability to manipulate fluids of picolitres or smaller volumes through nanoscale apertures near the cantilever tip. Each channel is connected to a separate fluid reservoir, which can be independently controlled by pressure. Various systematic experiments with fluorescent liquids were done by either injecting the liquids from the on-chip reservoir or aspirating directly through the nanoscale apertures at the tip. A flow rate analysis of volume dosing, aspiration and concentration dosing inside the liquid medium was performed. To understand the fluid behaviour, an analytical model based on the hydrodynamic resistance, as well as numerical flow simulations of single and multi-phase conditions were performed and compared. By applying pressures between -500 mbar and 500 mbar to the reservoirs of the probe with respect to the ambient pressure, flow rates ranging from 10 fl s-1 to 83 pl s-1 were obtained inside the channels of the cantilever as predicted by the analytical model. The smallest dosing flow rate through the apertures was 720 fl s-1, which was obtained with a 10 mbar pressure on one reservoir and ambient pressure on the other. The solute concentration in the outflow could be tuned to values between 0% and 100% by pure convection and to values between 17.5% and 90% in combination with diffusion. The results prove that this new probe enables handling multiple fluids with the scope to inject different concentrations of analytes inside a single living cell and also perform regular AFM functionalities.
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Volume and concentration dosing in picolitres using a two-channel microfluidic AFM cantilever.
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Nanoscale
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engineering
| 1,895 | 26 |
The utilization of refractive index (RI) change due to guest-host interactions between the guest volatile organic compound vapor and porous metal-organic frameworks (vapor-MOF interactions) is promising in photonic vapor sensors. Therefore, the study of light-matter interactions in nanoporous metal-organic frameworks (MOFs) is fundamental and essential for MOF-based photonic devices. In this work, the manipulation of light in MOFs to investigate the vapor-MOF interactions by using optical fiber devices is demonstrated. The vapor-MOF interactions and the light-vapor interactions (light in MOFs to sense the RI changes resulting from the vapor-MOF interactions) are investigated. The cladding mode is excited by a long-period fiber grating (LPFG) for evanescent field sensing in a ZIF-8 sensitive coating. The experimental results combining quantum chemical calculations and optical simulations reveal the relationships between the microscopic energy of vapor desorption, RI changes and evanescent field enhancement in ZIF-8 during the vapor-MOF interactions. With exceptionally large RI changes, the evanescent field of cladding mode in ZIF-8 is greatly enhanced to sense the vapor-MOF interactions. As a proof-of-concept, a LPFG sensor with ZIF-8 coating showed a high sensitivity of 1.33 pm ppm-1 in the linear range from 9.8 ppm to 540 ppm for the sensing of ethanol vapor. The investigation of light-matter interactions in ZIF-8 provides a useful guideline for the design and fabrication of MOF-based optical waveguide/fiber sensors.
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Nanoscale light-matter interactions in metal-organic frameworks cladding optical fibers.
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Nanoscale
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engineering
| 1,895 | 26 |
All-dielectric resonant micro- and nano-structures made of high-index dielectrics have recently emerged as a promising surface-enhanced Raman scattering (SERS) platform which can complement or potentially replace the metal-based counterparts in routine sensing measurements. These unique structures combine the highly-tunable optical response and high field enhancement with the non-invasiveness, i.e. chemically non-perturbing the analyte, simple chemical modification and recyclability. Meanwhile, commercially competitive fabrication technologies for mass production of such structures are still missing. Here, we attest a chemically inert black silicon (b-Si) substrate consisting of randomly-arranged spiky Mie resonators for a true non-invasive (chemically non-perturbing) SERS identification of the molecular fingerprints at low concentrations. Based on the comparative in situ SERS tracking of the para-aminothiophenol (PATP)-to-4,4'-dimercaptoazobenzene (DMAB) catalytic conversion on the bare and metal-coated b-Si, we justify the applicability of the metal-free b-Si for ultra-sensitive non-invasive SERS detection at a concentration level as low as 10-6 M. We performed supporting finite-difference time-domain (FDTD) calculations to reveal the electromagnetic enhancement provided by an isolated spiky Si resonator in the visible spectral range. Additional comparative SERS studies of the PATP-to-DMAB conversion performed with a chemically active bare black copper oxide (b-CuO) substrate as well as SERS detection of the slow daylight-driven PATP-to-DMAB catalytic conversion in the aqueous methanol solution loaded with colloidal silver nanoparticles (Ag NPs) confirm the non-invasive SERS performance of the all-dielectric crystalline b-Si substrate. A proposed SERS substrate can be fabricated using the easy-to-implement scalable technology of plasma etching amenable on substrate areas over 10 × 10 cm2 making such inexpensive all-dielectric substrates promising for routine SERS applications, where the non-invasiveness is of high importance.
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Chemically non-perturbing SERS detection of a catalytic reaction with black silicon.
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Nanoscale
|
engineering
| 1,895 | 26 |
Fe-N-C series catalysts are always attractive for their high catalytic activity towards the oxygen reduction reaction (ORR). However, they usually consist of various components such as iron nitrides, metallic iron, iron carbides, N-doped carbon and Fe-N 4 moieties, leading to controversial contributions of these components to the catalysis of the ORR, especially iron nitrides. In this work, to investigate the function of iron nitrides, Fe x N nanoparticles (NPs) embedded in mesoporous N-doped carbon without Fe-N 4 moieties are designed and constructed by a simple histidine-assisted method. Herein, the use of histidine can increase the N and Fe contents in the product. The obtained catalyst exhibits excellent ORR catalytic activity which is very close to that of the commercial Pt/C catalyst in alkaline electrolytes. Combining the catalytic activity, structural characterization (especially from Mössbauer spectroscopy), and the results of DFT calculations for adsorption energies of oxygen on the main surfaces of Fe 2 N including ε-Fe 2 N and ζ-Fe 2 N, it can be deduced that Fe 2 N NPs as active species make a contribution to the ORR catalysis, of which ε-Fe x N (x ≤ 2.1) is more active than ζ-Fe 2 N. In addition, we find that there exists an obvious synergistic effect between Fe 2 N NPs and N-doped carbon, leading to the greatly enhanced ORR catalytic activity.
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The role of iron nitrides in the Fe-N-C catalysis system towards the oxygen reduction reaction.
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Nanoscale
|
engineering
| 1,895 | 26 |
The switchability of electrical properties has recently attracted much attention due to its potential applications in memory, sensors, and resistive switches. Here, a solution-phase synthesis of iron telluride nanostructures with reversible and reproducible switching behavior between p- and n-type conduction is demonstrated by a simple change of temperature without crystal structure changes. The transition temperature of FeTe2 to switch from p-type to n-type is strongly dependent on the original ratio of the precursors and sintering time. Further studies confirm that the switching is derived from the valence change effect and a proof-of-concept thermally triggered p-n diode has been demonstrated.
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Solution-phase synthesized iron telluride nanostructures with controllable thermally triggered p-type to n-type transition.
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Nanoscale
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engineering
| 1,895 | 26 |
Metal nanocrystals (NCs) have been recognized as an important class of nanomaterials by virtue of their unique surface plasmon resonance (SPR) effect and pivotal roles as electron traps in photocatalysis. Nevertheless, it is still challenging to unambiguously unravel and simultaneously harness the dual synergistic roles of metal NCs in a single photocatalytic system for solar-to-chemical energy conversion. Herein, an efficient ligand-triggered electrostatic self-assembly strategy was developed to achieve the spontaneous and monodispersed attachment of Au NCs onto 1D WO 3 nanorods (NRs) via pronounced electrostatic attractive interaction, in which tailor-made positively charged Au NCs were closely integrated with negatively charged WO 3 NRs. The intimate integration of Au NCs with WO 3 NRs at the nanoscale could significantly benefit the extraction, separation, and migration of plasmon-induced energetic hot carriers over Au NCs and promote the separation of photogenerated charge carriers over the WO 3 substrate. Such a cooperative synergy stemming from SPR and the electron-withdrawal effects of the Au NCs resulted in distinctly enhanced photoredox catalytic performances for plasmonic photocatalysis under both simulated solar and visible light irradiation. Our study highlights the significance of utilizing a rational interface design between metal NCs and semiconductors for excavating the multifarious roles of metal NCs in substantial solar energy conversion.
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Self-assembly of metal/semiconductor heterostructures via ligand engineering: unravelling the synergistic dual roles of metal nanocrystals toward plasmonic photoredox catalysis.
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Nanoscale
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engineering
| 1,895 | 26 |
Developing earth-abundant and highly efficient electrocatalysts is critical for further development of a system. The metal (M) doping strategy and inorganic/organic composite are two common strategies to improve the performance of electrocatalysts for overall water splitting (OWS). In this paper, two strategies are subtly used to prepare Mo-Ni 3 S 2 quantum dots (QDs) with rich sulfur defects through Mo n+ doping Ni 3 S 2 and introduction of trisodium citrate by a two-step hydrothermal reaction. Results show that high sulfur defects can be controllably prepared as the lattice mismatch and active sites can be efficiently increased via Mo n+ doping. Moreover, the introduction of trisodium citrate with carboxyl functional groups not only enhances the degree of sulfur defects around the metal center, changes the morphology of sulfide to distribute the active centers evenly, but also endow the metal center with strong valence changing ability with organic characteristics. The in situ Raman study reveals that O-C[double bond, length as m-dash]O promotes the formation of the real active site M-OOH by the way of self-sacrifice during the OER process. Mo-Ni 3 S 2 QDelectrocatalyst shows excellent performance in the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), achieving a current density of 10 mA cm -2 at the overpotentials of 115 mV and 222 mV with very good chemical stability, superior than that of most of the reported materials. The OWS reaction can provide a current density of 10 mA cm -2 and 50 mA cm -2 , which only needs 1.53 V and 1.74 V with excellent industrial application prospects.
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Sulfur defect rich Mo-Ni3S2 QDs assisted by O-C[double bond, length as m-dash]O chemical bonding for an efficient electrocatalytic overall water splitting.
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Nanoscale
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engineering
| 1,895 | 26 |
Gold films do not adhere well on glass substrates, so plasmonics experiments typically use a thin adhesion layer of titanium or chromium to ensure a proper adhesion between the gold film and the glass substrate. While the absorption of light into gold structures is largely used to generate heat and control the temperature at the nanoscale, the influence of the adhesion layer on this process is largely overlooked. Here, we quantify the role of the adhesion layer in determining the local temperature increase around a single nanohole illuminated by a focused infrared laser. Despite their nanometer thickness, adhesion layers can absorb a greater fraction of the incoming infrared light than the 100 nm thick gold layer leading to a significant increase of the local temperature. Different experimental designs are explored, offering new ways to promote or avoid the temperature increase inside nanoapertures. This knowledge further expands the plasmonic toolbox for temperature-controlled experiments including single molecule sensing, nanopore translocation, polymerization, or nano-optical trapping.
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Adhesion layer influence on controlling the local temperature in plasmonic gold nanoholes.
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Nanoscale
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engineering
| 1,895 | 26 |
We investigate the impact of nanoparticle roughness on the phase behaviour of suspensions in models of calcium carbonate nanoparticles. We use a Derjaguin approach that incorporates roughness effects and interactions between the nanoparticles modelled with a combination of DLVO forces and hydration forces, derived using experimental data and atomistic molecular dynamics simulations, respectively. Roughness effects, such as atomic steps or terraces appearing in mineral surfaces result in very different effective inter-nanoparticle potentials. Using stochastic Langevin Dynamics computer simulations and the effective interparticle interactions we demonstrate that relatively small changes in the roughness of the particles modify significantly the stability of the suspensions. We propose that the sensitivity of the phase behavior to the roughness is connected to the short length scale of the adhesive attraction arising from the ordering of water layers confined between calcite surfaces. Particles with smooth surfaces feature strong adhesive forces, and form gel fractal structures, while small surface roughness, of the order of atomic steps in mineral faces, stabilize the suspension. We believe that our work helps to rationalize the contrasting experimental results that have been obtained recently using nanoparticles or extended surfaces, which provide support for the existence of adhesive or repulsive interactions, respectively. We further use our model to analyze the synergistic effects of roughness, pH and ion concentration on the phase behavior of suspensions, connecting with recent experiments using calcium carbonate nanoparticles.
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The influence of surface roughness on the adhesive interactions and phase behavior of suspensions of calcite nanoparticles.
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Nanoscale
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engineering
| 1,895 | 26 |
Fullerene microcrystals have been well prepared by the conventional liquid-liquid interface precipitation (LLIP) method, and the crystal structures can be manipulated by solvent combination. Aromatic and alcoholic solvents are widely used as good and poor solvents, respectively, in LLIP. However, water with higher polarity has been rarely utilized as a poor solvent for the morphology engineering of fullerenes, particularly in the morphology control of fullerene derivatives. Herein, the water-regulated morphology of a fullerene derivative, namely ferrocenylpyrrolidine C 60 (denoted as FC), is investigated via the LLIP method. By simply modulating the combination of a good solvent (aromatic isopropylbenzene, IPB) and the poor solvents (alcohols), three-dimensional (3D) hierarchical microspheres of FC are obtained. Surprisingly, when water is introduced as one of poor solvents in the LLIP process, one-dimensional (1D) microneedles are obtained. The presence of water controls the liquid-liquid interface, the external environment and kinetics of the crystal growth, thereby promoting the morphological evolution from 3D hierarchical microspheres to 1D microneedles. Moreover, the solvated 1D microneedles exhibit enhanced photoluminescence (PL) and photocurrent responses in virtue of the highly ordered molecule arrangement and solvent (IPB) embedding in the crystal lattice. The water-regulated morphology engineering of FC provides a new strategy for the growth and morphology control of fullerene microcrystals.
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From 3D hierarchical microspheres to 1D microneedles: the unique role of water in the morphology control of ferrocenylpyrrolidine C60 microcrystals.
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Nanoscale
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engineering
| 1,895 | 26 |
MoS 2 nanoparticles are typically obtained by high temperature sulfurization of organic and inorganic precursors under a S rich atmosphere and have excellent friction reduction properties. We present a novel approach for making the sulfurization unnecessary for MoO 3 nanotubes during the synthesis process for friction and wear reduction applications while simultaneously achieving a superb tribological performance. To this end, we report the first in situ sulfurization of MoO 3 nanotubes during sliding contact in the presence of sulfur-containing lubricant additives. The sulfurization leads to the tribo-chemical formation of a MoS 2 -rich low-friction tribofilm as verified using Raman spectroscopy and can be achieved both during sliding contact and under extreme pressure conditions. Under sliding contact conditions, MoO 3 nanotubes in synergy with sulfurized olefin polysulfide and pre-formed zinc dialkyl dithiophosphate tribofilms achieve an excellent friction performance. Under these conditions, the tribochemical sulfurization of MoO 3 nanotubes leads to a similar coefficient of friction to the one obtained using a model nanolubricant containing MoS 2 nanotubes. Under extreme pressure conditions, the in situ sulfurization of MoO 3 nanotubes using sulfurized olefin polysulfide results in a superb load carrying capacity capable of outperforming MoS 2 nanotubes. The reason is that while MoO 3 nanotubes are able to continuously sulfurize during sliding contact conditions, MoS 2 nanotubes progressively degrade by oxidation thus losing lubricity.
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In situ tribochemical sulfurization of molybdenum oxide nanotubes.
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Nanoscale
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engineering
| 1,895 | 26 |
Gold nanoparticle (Au NP) incorporated photonic crystals (PCs) have been extensively studied due to the intricate interplay between the surface plasmon resonance of Au NPs and the periodic nanostructure of PCs. Herein, we successfully synthesized Au NP decorated poly(styrene-co-(generation 3 carbosilane-thioether vinyl-terminated dendrimer)) (P(st-co-G3Vi)) microspheres via in situ reduction of Au ions based on the strong coordination between the Au ions and the sulfur atom in G3Vi dendrimers. These composite Au-doped microspheres demonstrate a bumpy surface topography, which gives rise to a higher hydrophobicity and could effectively suppress the formation of an ubiquitous coffee-ring during the drying process of a colloidal suspension. More importantly, layer-controllable PCs were constructed with Au-doped microspheres by combining the Langmuir-Blodgett method with a layer-by-layer stacking strategy. By manipulating the stacking layers and diameters of microspheres, multifarious PCs with different photonic band gaps and reflection intensities were obtained, which can serve as an effective substrate for amplified quantum dot fluorescence. Further investigation reveals that fluorescence could be significantly pronounced by five-layer PCs. This work offers a facile and reproducible strategy to prepare Au NP incorporated PCs by in situ synthesis of Au NPs within dendrimer-functionalized microspheres, resulting in an enhancement of quantum dot fluorescence, which will lead to promising applications in energy-saving optoelectronic devices.
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Gold-loaded microspheres via carbosilane-thioether dendrimers as stabilizers and their performance in layer-controllable photonic crystals.
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Nanoscale
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engineering
| 1,895 | 26 |
In recent years, it is prevalent to treat various kinds of the tumors through microwave ablation method. However, it is still very difficult to ablate large tumors by the traditional microwave ablation therapy. In this work, an effective microwave embolization agent designed by encapsulating molybdenum sulfide nanosheets in the sodium alginate microcapsules, denoted as MSMCs, was prepared for the effective therapy of large tumor. The toxicity evaluation showed that MSMC had a good biocompatibility in vitro. The in vitro and in vivo experiments demonstrated that the MSMC was an excellent embolic and microwave susceptible agent that could be used for dual-enhanced microwave ablation therapy. As such, the MSMC showed excellent tumor therapeutic effect with 5 times larger ablation zone observed by magnetic resonance (MR) imaging than the microwave alone after 3 days treating. Besides, the tumor is nearly completely ablated and can not be recurrent due to the persistent hyperthermia. Moreover, MSMCs have a good biocompatibility and can be degraded and cleared from the body. It is believed that the MSMC is demonstrated to be a promising multifunctional theranostic agent used for treating the larger tumor via the synergistic therapy of enhanced microwave ablation and transcatheter arterial embolization (TAE).
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MoS2 nanosheets encapsulated in sodium alginate microcapsules as microwave embolization agents for large orthotopic transplantation tumor therapy.
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Nanoscale
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engineering
| 1,895 | 26 |
Under the action of pump light, a conventional photonic crystal can be turned into a functional photonic crystal. In the paper, we have designed an optical triode with a one-dimensional functional photonic crystal, and analyzed the effect of period number, medium thickness, refractive index, incident angle, the irradiation frequency and the intensity of the pump light on the optical triode magnification. We obtain some valuable results, which shall help to optimize the design of optical triodes.
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The design of an optical triode.
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Nanoscale
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engineering
| 1,895 | 26 |
Although there has been significant progress in the development of tumor immunotherapies, many challenges still exist for the treatment of solid tumors. Natural killer (NK) cells possess broad-spectrum cytotoxicity against tumors, but their limited migration and infiltration abilities restrict their application in solid tumor therapies. Here, we combined a facile and efficient magnetic-targeting strategy with NK cell-based therapy to develop a novel immunotherapy approach for treating solid tumors. Anti-CD56 antibodies were conjugated with Fe 3 O 4 nanoparticles, which could specifically bind with NK-92 cells endowing them with a magnetic field driven targeting ability. These NK-Fe 3 O 4 biohybrid nanoparticles were able to facilitate directional migration to the tumor site in vivo under external magnetic field guidance and efficiently inhibit tumor growth. These functionalized NK cells represent a novel approach for solid tumor therapy and may provide a promising modality for cancer interventions in the future.
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Surface specifically modified NK-92 cells with CD56 antibody conjugated superparamagnetic Fe3O4 nanoparticles for magnetic targeting immunotherapy of solid tumors.
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Nanoscale
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engineering
| 1,895 | 26 |
This work addresses how G5.5 PAMAM dendrimers form complexes with bovine serum albumin (BSA). Analytical techniques, such as UV-vis spectrophotometry, dynamic light scattering, electrophoretic mobility, quartz crystal microbalance with dissipation monitoring (QCM-D), circular dichroism (CD), and contact angle were used to analyze the properties of the dendrimers systems. The binding of protein to dendrimers can alter the structure, mobility, conformation and functional activity of the dendrimer. The results show that BSA interactions with G5.5 dendrimer carriers are driven both by electrostatic and hydrophobic forces. Dendrimer surface charge is reduced upon contact with the protein. The protein shell formed on the surface of the carrier is very stable as evidenced by the QCM-D measurements. On the other hand, the CD spectra indicates a change in the secondary structure of the protein. The size of the changes is significantly dependent on the ratio of protein to dendrimer. Understanding the mechanism of interaction of potential carriers with proteins is important for their internalization into the cell.
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Analysis of dendrimer-protein interactions and their implications on potential applications of dendrimers in nanomedicine.
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Nanoscale
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engineering
| 1,895 | 26 |
We carefully prepared interfacial Al-doped (IAD) and interfacial natively-doped (IND) ZnO nanowires (NWs) by introducing atomic-layer interfacial Δ-doping between the two steps of CVD growth. Variable-temperature electron transport as well as magnetotransport behaviours of these NWs were systematically investigated. By virtue of the unique architecture and the quality-guaranteed growth technique, a series of quantum interference effects were clearly observed in the IAD ZnO NWs, including weak localization, universal conductance fluctuation and Altshuler-Aronov-Spivak oscillations. The phase-coherence length (L φ ) of electrons exceeds 100 nm in the IAD ZnO NWs, much longer than those in the IND ones and most conventionally doped ZnO NWs. This ability to efficiently manipulate a variety of quantum interference effects in ZnO NWs is very desirable for applications in nano-optoelectronics, nano- & quantum-electronics and solid-state quantum computing.
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Manipulating the quantum interference effect and magnetotransport of ZnO nanowires through interfacial doping.
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Nanoscale
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engineering
| 1,895 | 26 |
Here we describe a facile, one-step synthesis of a binary organic nanoparticle composed completely of NIR-absorbing small molecules, a quatterylene diimide and a vanadyl napthalocyanine, using Flash Nanoprecipitation. We show that the molecules are co-encapsulated within an amphiphilic block copolymer shell by observing distinct ultrafast dynamics in the binary nanoparticles compared to nanoparticles of their individual components, which we rationalize as a photoinduced charge transfer. We then draw similarities between the charge transfer dynamics studied in our system and the charge dissociation process in macroscale organic bulk heterojunction blends for OPV applications by assigning the ultrafast time component (∼10 ps) to direct interfacial charge transfer and the slow component (70-200 ps) to diffusion limited charge transfer. This discovery can inspire the development of mixed-composition nanoparticles with new functionality for optoelectronic and theranostic applications.
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Binary small molecule organic nanoparticles exhibit both direct and diffusion-limited ultrafast charge transfer with NIR excitation.
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Nanoscale
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engineering
| 1,895 | 26 |
Cadmium-free quantum dots (QD) were combined with crystal violet photosensitising dye and incorporated into medical grade polyurethane via a non-covalent dipping process known as 'swell-encapsulation-shrink'. The antibacterial efficacy of the prepared quantum dot-crystal violet polyurethane substrates (QD + CV PU) was investigated under low power visible light illumination at similar intensities (500 lux) to those present in clinical settings. The antibacterial performance of QD + CV PU was superior to the constituent polymer substrates, eliminating ∼99.9% of an environmental P. aeruginosa strain, a clinical P. aeruginosa strain from a cystic fibrosis patient and a clinical E. coli strain. The nature of the reactive oxygen species (ROS) involved in antibacterial activity of the QD + CV PU surface was investigated using ROS inhibitors and time-resolved optical spectroscopy. The photo-physical interactions of the green-emitting QDs with CV lead to a combination of Type I and II electron transfer and energy transfer processes, with the highly potent ROS singlet oxygen playing a dominant role. This study is the first to demonstrate highly efficient synergistic killing of clinical and environmental strains of intrinsically resistant and multi-drug resistant Gram-negative bacteria using light-activated surfaces containing biocompatible cadmium-free QDs and crystal violet dye at ambient light levels.
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Synergistic interactions of cadmium-free quantum dots embedded in a photosensitised polymer surface: efficient killing of multidrug-resistant strains at low ambient light levels.
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Nanoscale
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engineering
| 1,895 | 26 |
The amplification of light in NIR-II from Ag2S QDs via metal enhanced fluorescence (MEF) is reported for the first time. Significant fluorescence enhancement of over 100 times for Ag2S QDs deposited on Au-nanostructured arrays, paves the way for novel sensing and imaging applications based on Ag2S QDs, with improved detection sensitivity and contrast enhancement.
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Significant metal enhanced fluorescence of Ag2S quantum dots in the second near-infrared window.
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Nanoscale
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engineering
| 1,895 | 26 |
Even though immunological checkpoint inhibitors have demonstrated a potent anti-tumor effect in clinical practice, the low immunogenicity of the majority of tumors still results in a lower response rate and a higher resistance to mono-immunotherapy. Recent studies revealed that immunogenic cell death (ICD) augments T cell responses against some cancers, thus indicating that this combination therapy may further improve the anti-tumor immunity produced by anti-PD-1/PD-L1. Herein a robust synergetic strategy is reported to integrate the activation of necroptotic cell death and the subsequent using of immune checkpoint inhibitors. Liposomes have good biocompatibility and are widely used as drug carriers. Using liposomes as TNF-α-loaded nanoplatforms achieves in vivo tumor targeting and long-term retention in the tumor microenvironment. Tumor cells treated with TNF-α-loaded liposomes exhibited the hallmarks of ICD including the release of high mobility group box 1 (HMGB1) and lactate dehydrogenase (LDH). Additionally, the tumor cell necrosis caused by TNF-α induces the in situ release of tumor-specific antigens, thus increasing the dendritic cell (DC) activation and T cell infiltration when combined with the checkpoint blockade therapy. Collectively, significant tumor reduction is accomplishable by this synergetic strategy, in which TNF-α-loaded liposomes convert the tumor cell into an endogenous vaccine and improve the anti-tumor immunity of anti-PD-1/PD-L1.
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Nanocarrier-based activation of necroptotic cell death potentiates cancer immunotherapy.
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Nanoscale
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engineering
| 1,895 | 26 |
Magnetic assemblies with special morphologies are promising for versatile biomedical applications due to their intriguing properties and performances. In this work, a polycation-functionalized bowl-shaped magnetic assembly (b-MNP-PGEA) was constructed for magnetic resonance imaging (MRI)-guided synergistic cancer therapy. Taking advantage of distinct properties of Fe 3 O 4 nanoparticles, self-assembly concept, morphology control, and appropriate surface functionalization, the as-prepared magnetic assembly with special morphology was expected to work as a multifunctional carrier to realize the combination of magnetofection and photothermal therapy (PTT). The morphology effect of the magnetic assembly on cellular uptake and the subsequent gene transfection were investigated. The feasibility of the magnetic and photothermal carriers for MRI and complementary PTT/gene therapy was also studied. In addition, the excellent in vivo performance of the proposed bowl-shaped multifunctional carriers was demonstrated using a mouse breast cancer model. Interestingly, synergistic effects based on PTT-enhanced gene therapy were achieved. The facile assembly strategy for the development of special bowl-shaped magnetic carriers for synergistic PTT/gene therapy provides a new avenue for the versatile construction of efficient theranostic platforms.
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A flexible bowl-shaped magnetic assembly for multifunctional gene delivery systems.
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Nanoscale
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engineering
| 1,895 | 26 |
Large banks of cheap, fast, non-volatile, energy efficient, scalable solid-state memories are an increasingly essential component for today's data intensive computing. Conductive-bridge random access memory (CBRAM) - which involves voltage driven formation and dissolution of Cu or Ag filaments in a Cu (or Ag) anode/dielectric (HfO2 or Al2O3)/inert cathode device - possesses the necessary attributes to fit the requirements. Cu and Ag are, however, fast diffusers and known contaminants in silicon microelectronics. Herein, employing a criterion for electrode metal selection applicable to cationic filamentary devices and using first principles calculations for estimating diffusion barriers in HfO2, we identify tin (Sn) as a rational, silicon CMOS compatible replacement for Cu and Ag anodes in CBRAM devices. We then experimentally fabricate Sn based CBRAM devices and demonstrate very fast, steep-slope memory switching as well as threshold switching, comparable to Cu or Ag based devices. Furthermore, time evolution of the cationic filament formation along with the switching mechanism is discussed based on time domain measurements (I vs. t) carried out under constant voltage stress. The time to threshold is shown to be a function of both the voltage stress (Vstress) as well as the initial leakage current (I0) through the device.
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Silicon compatible Sn-based resistive switching memory.
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Nanoscale
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engineering
| 1,895 | 26 |
High-quality hexagonal NaYF4:Yb,Tm upconversion nanocrystals (UCNs) prepared in organic solutions display uniform sizes and strong UC emissions, but they possess a hydrophobic surface which hinders combining them with various semiconductor nanocrystals (NCs) to form a hybrid NIR-activated photocatalyst. Herein we present a facile approach to modify hydrophobic UCNs with a uniform carbon layer and enable them with hydrophilicity and surface functionalization. The carbon shell provides a good substrate for enriching with metal ions and in situ generation of CdS nanoclusters on the particle surface which can utilize both the upconverted UV and visible emissions. The developed NaYF4:Yb,Tm@C@CdS nanoparticles are characterized with TEM, SEM, XRD, PL and UV-Vis spectra and their formation mechanism is elucidated. The products display good photocatalytic activity under visible light and obviously enhanced performance under Vis-NIR light, due to the efficient utilization of UC emissions and the strong adsorption capacity of the carbon shell. The working mechanism of the hybrid photocatalysts is also proposed.
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Depositing CdS nanoclusters on carbon-modified NaYF4:Yb,Tm upconversion nanocrystals for NIR-light enhanced photocatalysis.
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Nanoscale
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engineering
| 1,895 | 26 |
Three-dimensional (3D) networked nanomaterials have attracted great interest because of their unique porous and 3D-networked structures. In this work, a series of gold nanoparticle (AuNP) doped graphene hydrogel nanocomposites (AuNP-GHs) were synthesized through hydrothermal reaction under various conditions. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) were used to characterize the AuNP-GH. The AuNP-GH was used to modify the glassy carbon electrode (GCE) for the detection of indole-3-acetic acid (IAA) and salicylic acid (SA) using chronoamperometric measurements. Under optimum conditions, the AuNP-GH/GCE exhibited linear response to IAA in the ranges of 0.8-4 μM and 4-128 μM, and to SA in the ranges of 0.8-8.4 μM and 8.4-188.4 μM. The detection limits (S/N = 3) were calculated to be 0.21 μM for IAA and 0.22 μM for SA. The proposed sensor showed good sensitivity and stability and hence it was applied in the detection of IAA and SA in spiked samples with satisfactory results.
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Gold nanoparticle-doped three-dimensional reduced graphene hydrogel modified electrodes for amperometric determination of indole-3-acetic acid and salicylic acid.
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Nanoscale
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engineering
| 1,895 | 26 |
In alkaline solution, the electrocatalytic oxygen evolution reaction (OER) of dual transition metal atom (2TM) nitrogen-decorated graphene as a double-atom catalyst (DAC) has received special attention. Here, using density functional theory (DFT) calculations, the OER electrocatalysis of 2TM-pyridine/amino-nitrogen-decorated graphene (2TM-N PA G and 2TM-N P G. 2TM represents FeCo, FeNi, Conti) is studied. The electrocatalytic OER mechanism is that 2TM-N P G acts as the pre-catalyst, while the real catalysts are 2TM-N PA G and 2TM-N P G-O. In particular, CoNi-N PA G and CoNi-N P G-O exhibit higher OER activity compared to state-of-the-art RuO 2 at pH = 14. It is confirmed that the potential-determining step is also the rate-determining step. Amino-nitrogen is the main accepter of electrons from CoNi atoms and pyridine-nitrogen is the main acceptor of electrons from nearby C atoms. The role of different N coordination continues to influence the entire electrocatalytic OER process of CoNi-NG. Simultaneously, the overpotential of CoNi-NG is in a volcano-shaped relationship with the electronic properties (oxidation state or d-band center) of the catalytic site of Co. Moreover, CoNi-N PA G and CoNi-N P G-O are the closest to the center of the OER overpotential (a function of the d-band center and oxidation state) contour plot, implying that they exhibit the best catalytic activity among all the CoNi-NG materials. The optimal electronic properties of CoNi-N PA G and CoNi-N P G-O contribute towards their excellent OER performance, and provide a new breakthrough in developing high-performance DACs.
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Electronic properties of double-atom catalysts for electrocatalytic oxygen evolution reaction in alkaline solution: a DFT study.
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Nanoscale
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engineering
| 1,895 | 26 |
Recently, alkyl radicals have attracted much attention in cancer therapy due to their oxygen-independent generation property. For the first time, alkyl radical and nitric oxide (NO) combined therapy is demonstrated as an effective strategy for tumor inhibition. As a proof of concept, a biocompatible free radical nanogenerator with near-infrared (NIR) II laser-induced simultaneous NO and alkyl radical release property was elaborately fabricated. In particular, an NIR II molecule (IR 1061), NO donor (BNN6) and alkyl radical initiator (AIPH) were firstly encapsulated in a natural lecithin stabilized phase change material, and then further functionalized by an amphiphile of DSPE-PEG-RGD with specific tumor targeting ability, finally obtaining biocompatible P(IR/BNN6/AIPH)@Lip-RGD. Upon NIR II laser irradiation, the photothermal effect generated from IR 1061 could trigger the phase change of the nanogenerator by releasing the encapsulated BNN6 and AIPH, and subsequently decompose them to generate highly active NO and alkyl radicals. Remarkably, NO and alkyl radical release profiles of P(IR/BNN6/AIPH)@Lip-RGD could be precisely controlled using intermittent NIR II laser irradiation. Moreover, P(IR/BNN6/AIPH)@Lip-RGD displayed a synergistic NO and alkyl radicals' anticancer effect by significantly inhibiting the growth of breast tumors, upon NIR II laser exposure. Furthermore, an in depth mechanistic study revealed that synergistic NO and alkyl radical effect induced cancer cell apoptosis through a mitochondria-mediated apoptotic pathway. The synergistic effect jointly caused a burst generation of mitochondrial ROS, which significantly down-regulated Bcl-2 protein expression, accelerated cytochrome c release and triggered a cascade of apoptosis-related proteins of Caspase-3 and Caspase-9.
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Near infrared II laser controlled free radical releasing nanogenerator for synergistic nitric oxide and alkyl radical therapy of breast cancer.
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Nanoscale
|
engineering
| 1,895 | 26 |
Atherosclerosis, a major macrovascular complication associated with diabetes, poses a tremendous burden on national health care expenditure. Despite extensive efforts, cost-effective remedies are unknown. Therapies for atherosclerosis are challenged by a lack of targeted drug delivery approaches. Toward this goal, we turn to a biology-derived drug delivery system utilizing nanoparticles formed by the plant virus, Cowpea mosaic virus (CPMV). The aim herein is to investigate the anti-atherogenic potential of the beneficial mineral nutrient, trivalent chromium, loaded CPMV nanoparticles in human aortic smooth muscle cells (HASMC) under hyperglycemic conditions. A non-covalent loading protocol is established yielding CrCl3-loaded CPMV (CPMV-Cr) carrying 2000 drug molecules per particle. Using immunofluorescence microscopy, we show that CPMV-Cr is readily taken up by HASMC in vitro. In glucose (25 mM)-stimulated cells, 100 nM CPMV-Cr inhibits HASMC proliferation concomitant to attenuated proliferating cell nuclear antigen (PCNA, proliferation marker) expression. This is accompanied by attenuation in high glucose-induced phospho-p38 and pAkt expression. Moreover, CPMV-Cr inhibits the expression of pro-inflammatory cytokines, transforming growth factor-β (TGF-β) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), in glucose-stimulated HASMCs. Finally glucose-stimulated lipid uptake is remarkably abrogated by CPMV-Cr, revealed by Oil Red O staining. Together, these data provide key cellular evidence for an atheroprotective effect of CPMV-Cr in vascular smooth muscle cells (VSMC) under hyperglycemic conditions that may promote novel therapeutic ventures for diabetic atherosclerosis.
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Anti-atherogenic effect of trivalent chromium-loaded CPMV nanoparticles in human aortic smooth muscle cells under hyperglycemic conditions in vitro.
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Nanoscale
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engineering
| 1,895 | 26 |
The addition of graphene nanoplatelets (GNP) to TiO2 nanoparticles (NPs) has been recently considered as a method to improve the photocatalytic efficiency of TiO2 by favoring charge carrier separation. Here, we show that it is possible to improve the efficiency of GNP-TiO2 composites by controlling the shape, stability, and facets of TiO2 NPs grown on GNP functionalized with either COOH or NH2 groups, while adding ethylendiamine (EDA) and oleic acid (OA) during a hydrothermal synthesis. We studied the photocatalytic activity of all synthesized materials under UV-A light using phenol as a target molecule. GNP-TiO2 composites synthesized on COOH-functionalized GNP, exposing {101} facets, were more efficient at abating phenol than those synthesized on NH2-functionalized GNP, exposing {101} and {100} facets. However, neither of these composites was stable under irradiation. The addition of both OA and EDA stabilized the materials under irradiation; however, only the composite prepared on COOH-functionalized GNP in the presence of EDA showed a significant increase in phenol degradation rate, leading to results that were better than those obtained with TiO2 alone. This result can be attributed to Ti-OH complexation by EDA, which protects GNP from oxidation. The orientation of the most reducing {101} facets toward GNP and the most oxidizing {100} facets toward the solution induces faster phenol degradation owing to a better separation of the charge carriers.
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Shape controllers enhance the efficiency of graphene-TiO2 hybrids in pollutant abatement.
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Nanoscale
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engineering
| 1,895 | 26 |
Analysis of single nucleotide variations (SNVs) in DNA and RNA sequences is instrumental in healthcare for the detection of genetic and infectious diseases and drug-resistant pathogens. Here we took advantage of the developments in DNA nanotechnology to design a hybridization sensor, named the 'owl sensor', which produces a fluorescence signal only when it complexes with fully complementary DNA or RNA analytes. The novelty of the owl sensor operation is that the selectivity of analyte recognition is, at least in part, determined by the structural rigidity and stability of the entire DNA nanostructure rather than exclusively by the stability of the analyte-probe duplex, as is the case for conventional hybridization probes. Using two DNA and two RNA analytes we demonstrated that owl sensors differentiate SNVs in a wide temperature range of 5 °C-32 °C, a performance unachievable by conventional hybridization probes including the molecular beacon probe. The owl sensor reliably detects cognate analytes even in the presence of 100 times excess of single base mismatched sequences. The approach, therefore, promises to add to the toolbox for the diagnosis of SNVs at ambient temperatures.
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The owl sensor: a 'fragile' DNA nanostructure for the analysis of single nucleotide variations.
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Nanoscale
|
engineering
| 1,895 | 26 |
As a coordination polymer built of [Mo 3 S 13 ] 2- clusters, amorphous nanoscale MoS x (a-MoS x ) is an attractive electrocatalyst for the hydrogen evolution reaction (HER) due to its abundant active sites and scalable synthesis. However, clarifying the internal catalytic mechanism and achieving even higher HER performance with scalable size are still challenging. Herein, a new hybrid catalyst of a-MoS x flakes decorated with Ni 3 S 2 nanocrystals (size < 10 nm) has been successfully synthesized on 10 × 20 cm 2 -sized Ni foam by a portable hydrothermal route. As the strong interaction of [Mo 3 S 13 ] 2- clusters with Ni 3 S 2 is evidenced by comprehensive binding state and Raman characterization, the polymerization effect of [Mo 3 S 13 ] 2- itself and the perfect interfaces between [Mo 3 S 13 ] 2- clusters and Ni 3 S 2 are also confirmed by density functional theory calculations. These two factors greatly lower the absorption energy of hydrogen nearly to zero, leading to much improved HER activity. Current densities of 100 and 600 mA cm -2 are achieved at overpotentials of 181 and 246 mV, respectively, which are so far the highest values approaching practical applications. The findings of this work provide a fundamental reference about the catalytic origin of a-MoS x based catalysts, and shed light on the practical applications of non-precious electrocatalysts for their compatibility with low cost batch production.
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Boosting the electrocatalytic activity of amorphous molybdenum sulfide nanoflakes via nickel sulfide decoration.
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Nanoscale
|
engineering
| 1,895 | 26 |
Photothermal therapy (PTT) is a promising cancer treatment with both high effectiveness and fewer side effects. However, an ideal PTT agent not only needs strong absorption of near-infrared (NIR) light and high photothermal conversion efficiency, but also needs good biocompatibility, stability, and small size, which makes the design and preparation of a novel PTT agent a great challenge. In this work, we developed an ultrasonication-assisted liquid exfoliation method for the direct preparation of ultrasmall (2-3 nm) MoSe2 nanodots (NDs) in aqueous solution and demonstrated their superior properties as a PTT agent. The as-prepared MoSe2 NDs have strong absorption of NIR light and high photothermal conversion efficiency of about 46.5%. In vitro cellular experiments demonstrate that MoSe2 NDs have negligible cytotoxicity and can efficiently kill HeLa cells (human cervical cell line) under NIR laser (785 nm) irradiation.
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Aqueous phase preparation of ultrasmall MoSe2 nanodots for efficient photothermal therapy of cancer cells.
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Nanoscale
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engineering
| 1,895 | 26 |
Artificial molecular machines synthesized in supramolecular chemistry have attracted great interest over the past decades. DNA origami presents an alternative approach to construct nano-machines by directly designing its thermodynamically stable state by DNA sequences. Here, we construct a molecular device, named NanoMuscle, with mechanically interlocked DNA origami. NanoMuscle's configuration - either extended or contracted - can be controlled by adding specific DNA strands. We monitored NanoMuscle's multistep synthesis with gel electrophoresis, and verified that monomers of the NanoMuscle are interlocked at correct orientation with transmission electron microscopy (TEM). We then validated that NanoMuscle can switch between extended and contracted configuration. By converting binding energy from DNA hybridization and Brownian motion to mechanical movements, NanoMuscle may serve as a novel building block for future mesoscale machinery.
|
NanoMuscle: controllable contraction and extension of mechanically interlocked DNA origami.
|
Nanoscale
|
engineering
| 1,895 | 26 |
The goal of this study was to assess how PD-L1 expression in tissue specimens of patients with main molecular subtypes of NMIBC (luminal, basal and double-negative p53-mutant) associates with relapsed-free survival in dependence on the tumor grade and prior treatment of primary bladder cancer. PD-L1 expressions on the membrane of neoplastic and CD8+ immune cells were assessed in tumor specimens ( n = 240) of primary and relapsed luminal, basal and double-negative p53-mutant NMIBC. Association between relapse-free survival and PD-L1 expression was estimated for high- and low-grade relapsed NMIBC according to previous treatment and their molecular profile, using the Kaplan-Meier method, and assessed by using the log-rank test. Potential confounders were adjusted by Cox regression models. In a group of patients who underwent only TUR without intravesical therapy, there were significant differences in relapse time between high- and low-grade tumors in basal and luminal molecular subtypes; for basal relapsed carcinoma, RFS was shorter in cases where tumors were less malignant. Both intravesical mitomycin and Bacillus Calmette-Guerin (BCG) therapy significantly extended the time of recurrence of low-grade luminal and basal bladder malignancies with no intergroup differences in double-negative NMIBC. PD-L1 expression status was associated with RFS for luminal relapsed NMIBCs in the group without previous frontline intervention, and with RFS in the group of patients with luminal relapsed bladder cancer previously utilized BCG. Obtained results may be considered as a promising approach for further clinical implementation.
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Relapse-Free Survival and PD-L1 Expression in First High- and Low-Grade Relapsed Luminal, Basal and Double-Negative P53-Mutant Non-Muscular Invasive Bladder Cancer Depending on Previous Chemo- and Immunotherapy.
|
Cancers
|
cancer
| 491 | 10 |
Waddington's epigenetic landscape, a famous metaphor in developmental biology, depicts how a stem cell progresses from an undifferentiated phenotype to a differentiated one. The concept of "landscape" in the context of dynamical systems theory represents a high-dimensional space, in which each cell phenotype is considered as an "attractor" that is determined by interactions between multiple molecular players, and is buffered against environmental fluctuations. In addition, biological noise is thought to play an important role during these cell-fate decisions and in fact controls transitions between different phenotypes. Here, we discuss the phenotypic transitions in cancer from a dynamical systems perspective and invoke the concept of "cancer attractors"-hidden stable states of the underlying regulatory network that are not occupied by normal cells. Phenotypic transitions in cancer occur at varying levels depending on the context. Using epithelial-to-mesenchymal transition (EMT), cancer stem-like properties, metabolic reprogramming and the emergence of therapy resistance as examples, we illustrate how phenotypic plasticity in cancer cells enables them to acquire hybrid phenotypes (such as hybrid epithelial/mesenchymal and hybrid metabolic phenotypes) that tend to be more aggressive and notoriously resilient to therapies such as chemotherapy and androgen-deprivation therapy. Furthermore, we highlight multiple factors that may give rise to phenotypic plasticity in cancer cells, such as (a) multi-stability or oscillatory behaviors governed by underlying regulatory networks involved in cell-fate decisions in cancer cells, and (b) network rewiring due to conformational dynamics of intrinsically disordered proteins (IDPs) that are highly enriched in cancer cells. We conclude by discussing why a therapeutic approach that promotes "recanalization", i.e., the exit from "cancer attractors" and re-entry into "normal attractors", is more likely to succeed rather than a conventional approach that targets individual molecules/pathways.
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Phenotypic Plasticity and Cell Fate Decisions in Cancer: Insights from Dynamical Systems Theory.
|
Cancers
|
cancer
| 491 | 10 |
Uveal melanoma (UM) is the most common primary intraocular tumor that arises from neoplastic melanocytes in the choroid, iris, and ciliary body. Electrochemotherapy (ECT) has been successfully established for the treatment of skin and soft tissue metastatic lesions, deep-seated tumors of the liver, bone metastases, and unresectable pancreas lesions. The aim of this study was to evaluate the effect of ECT in vitro in 3D spheroid culture systems in primary and metastatic UM cell lines. We also investigated the chick embryo chorioallantoic membrane (CAM) as an in vivo model system for the growth and treatment of UM tumors using ECT. The cytotoxic effect of ECT in 3D spheroids was analyzed seven days following treatment by assessment of the size and MTT [(3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) tetrazolium reduction] assay. The cytotoxicity of ECT after intratumoral or intraarterial administration was evaluated histologically. In vitro and in vivo ECT caused a significant reduction in tumor size and viability compared to electroporation or chemotherapy in both sections of our study. The current results underline the effectiveness of ECT in the treatment of UM and prepare the way for further investigation of its potential application in UM.
|
The Potential Use of Electrochemotherapy in the Treatment of Uveal Melanoma: In Vitro Results in 3D Tumor Cultures and In Vivo Results in a Chick Embryo Model.
|
Cancers
|
cancer
| 491 | 10 |
YAP and its paralog TAZ are the nuclear effectors of the Hippo tumour-suppressor pathway, and function as transcriptional co-activators to control gene expression in response to mechanical cues. To identify both common and unique transcriptional targets of YAP and TAZ in gastric cancer cells, we carried out RNA-sequencing analysis of overexpressed YAP or TAZ in the corresponding paralogous gene-knockouts (KOs), TAZ KO or YAP KO, respectively. Gene Ontology (GO) analysis of the YAP/TAZ-transcriptional targets revealed activation of genes involved in platelet biology and lipoprotein particle formation as targets that are common for both YAP and TAZ. However, the GO terms for cell-substrate junction were a unique function of YAP. Further, we found that YAP was indispensable for the gastric cancer cells to re-establish cell-substrate junctions on a rigid surface following prolonged culture on a soft substrate. Collectively, our study not only identifies common and unique transcriptional signatures of YAP and TAZ in gastric cancer cells but also reveals a dominant role for YAP over TAZ in the control of cell-substrate adhesion.
|
Common and Unique Transcription Signatures of YAP and TAZ in Gastric Cancer Cells.
|
Cancers
|
cancer
| 491 | 10 |
Pancreatic ductal adenocarcinoma (PDAC) is amongst the most fatal malignancies and its development is highly associated with inflammatory processes such as chronic pancreatitis (CP). Since the succinate dehydrogenase subunit B (SDHB) is regarded as tumor suppressor that is lost during cancer development, this study investigated the impact of M1-macrophages as part of the inflammatory microenvironment on the expression as well as function of SDHB in benign and premalignant pancreatic ductal epithelial cells (PDECs). Immunohistochemical analyses on pancreatic tissue sections from CP patients and control individuals revealed a stronger SDHB expression in ducts of CP tissues being associated with a greater abundance of macrophages compared to ducts in control tissues. Accordingly, indirect co-culture with M1-macrophages led to clearly elevated SDHB expression and SDH activity in benign H6c7-pBp and premalignant H6c7-kras PDECs. While siRNA-mediated SDHB knockdown in these cells did not affect glucose and lactate uptake after co-culture, SDHB knockdown significantly promoted PDEC growth which was associated with increased proliferation and decreased effector caspase activity particularly in co-cultured PDECs. Overall, these data indicate that SDHB expression and SDH activity are increased in PDECs when exposed to pro-inflammatory macrophages as a counterregulatory mechanism to prevent excessive PDEC growth triggered by the inflammatory environment.
|
Inflammation Associated Pancreatic Tumorigenesis: Upregulation of Succinate Dehydrogenase (Subunit B) Reduces Cell Growth of Pancreatic Ductal Epithelial Cells.
|
Cancers
|
cancer
| 491 | 10 |
Cancer is a common and complex disease with high incidence and mortality rates, which causes a severe public health problem worldwide. As one of the standard therapeutic approaches for cancer therapy, the prognosis and outcome of chemotherapy are still far from satisfactory due to the severe side effects and increasingly acquired resistance. The development of novel and effective treatment strategies to overcome chemoresistance is urgent for cancer therapy. Metabolic reprogramming is one of the hallmarks of cancer. Cancer cells could rewire metabolic pathways to facilitate tumorigenesis, tumor progression, and metastasis, as well as chemoresistance. The metabolic reprogramming may serve as a promising therapeutic strategy and rekindle the research enthusiasm for overcoming chemoresistance. This review focuses on emerging mechanisms underlying rewired metabolic pathways for cancer chemoresistance in terms of glucose and energy, lipid, amino acid, and nucleotide metabolisms, as well as other related metabolisms. In particular, we highlight the potential of traditional Chinese medicine as a chemosensitizer for cancer chemotherapy from the metabolic perspective. The perspectives of metabolic targeting to chemoresistance are also discussed. In conclusion, the elucidation of the underlying metabolic reprogramming mechanisms by which cancer cells develop chemoresistance and traditional Chinese medicines resensitize chemotherapy would provide us a new insight into developing promising therapeutics and scientific evidence for clinical use of traditional Chinese medicine as a chemosensitizer for cancer therapy.
|
Targeting Cancer Metabolism to Resensitize Chemotherapy: Potential Development of Cancer Chemosensitizers from Traditional Chinese Medicines.
|
Cancers
|
cancer
| 491 | 10 |
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